Angry NatWest customers probably will not be feeling too sympathetic. Still, experts in the Square Mile were yesterday attempting to work out just how much out of pocket Royal Bank of Scotland will be left by the computer cock-up that has frazzled its systems.
For one thing, there will be the cost of extending the opening hours of its branches, which were also open on Sunday. That, plus the fact RBS has promised to waive any fees incurred (how generous), will leave it with a bill in the tens of millions of pounds, according to Shore Capital's Gary Greenwood.
However, the analyst warned that this could end up moving into the hundreds of millions thanks to the possible cost of compensation. He calculated that if just 1 per cent of the bank's 17 million customers manage to claim £500 of compensation, that would total roughly £85m.
A big sum, no doubt, although Mr Greenwood was not too worried about the long-term effect on RBS.
"Although not insignificant, we believe a cost in the high tens or low hundreds of millions ... would be readily absorbed by the group," he claimed, adding that he did not think "reputational damage will be too significant or lasting".
The market seemed to concur. While RBS dipped 6.4p to 236.8p, rivals Lloyds and Barclays were worse off after being pegged back 0.98p to 30.41p and 6.45p to 194.25p respectively.
Of course, there is one way the group could recoup the sum it will lose. Stephen Hester, the state-owned bank's chief executive, has already said next year's bonuses will take into account the system meltdown – what are the chances of bosses taking all the hit?
Confidence ahead of the latest European Union summit, which starts on Thursday, was clearly not sky high as the FTSE 100 slumped 63.04 points to 5450.65. It continues a horrible run for the benchmark index in which it has shed over 3 per cent in just three sessions.
Shire was in the worst state, with the drugs maker looking rather sickly after sliding 223p to 1,743p. The cause was the approval by US regulators of a rival version of its blockbuster ADHD product Adderall XR, although optimistic City voices were suggesting the drop could make the favourite of the rumour mill more attractive to a potential bidder.
SABMiller's takeover hopes took a major hit. Speculation recently has suggested the Grolsch-brewer may be a target for Anheuser-Busch InBev, but it closed 41.5p worse off at 2,462.5p following talk its larger rival could instead be nearing a deal to buy the remaining 50 per cent of the Mexican owner of Corona, pictured, Grupo Modelo. The chatter prompted Liberum Capital's Pablo Zuanic to decide selling SAB's shares were a good idea, while he also attacked the fact the stock traded at a premium to rivals Heineken and Carlsberg.
Those blue-chip stocks that did manage to rise included Polymetal International. The Russian digger powered up 11.5p to 925p after Nomura's scribblers turned buyers in a positive note on the gold miners.
The scribes at Investec were also rather bullish on the sector as Centamin topped the FTSE 250.
The Egypt-focused group had been knocked last week by the delay to the country's presidential election results, but last night it closed 4.3p stronger at 68.85p in the wake of Mohammed Mursi being announced as the winner over the weekend.
A tough day for the oil explorers saw Premier Oil slip back 16.2p to 324p after announcing two of its wells had been plugged and abandoned. Meanwhile, Ophir Energy and Tullow Oil shifted down 23p to 590.5p and 24p to 1,407p despite Jefferies choosing them as among its favourite drillers.
Analysts at the broker were less keen on Cove Energy. The Mozambique-explorer has been boosted by hopes Royal Dutch Shell, 16p lower at 2,157.5p, will gazump PTT's 240p-a-pop takeover approach, but they warned that "it may not be in Shell's best interest to continue bidding up the price".
Still, many were choosing to ignore their advice. Thailand's PTT revealed it was pushing back the deadline for its offer after investors holding a mere 0.25 per cent of shares decided to accept, as Cove climbed a further 0.5p to 265.25p.
Elsewhere, Ithaca Energy was knocked back 14.5p to 95.5p after admitting a blockage had stopped oil flowing from one of the North Sea explorer's four production wells at its Athena Field.
FTSE 100 Risers
* Hargreaves Lansdown 513p (up 12p, 2.4 per cent) While fund manager finishes at the top of the benchmark index, the rise is not enough for it to recover the losses suffered over the past two sessions.
* Vodafone 178.6p (up 1p, 0.56 per cent) Mobile phone giant closes high up the leaderboard after getting a push from Barclays restarting its coverage with an "overweight" recommendation.
FTSE 100 Fallers
* Rio Tinto 2,872.5p (down 109.5p, 3.67 per cent) Digger retreats after scribes at UBS slash their earnings forecasts in preparation for incoming Australian mining and carbon taxes.
* WPP 743p (down 20p, 2.62 per cent) Sir Martin Sorrell's advertising giant finishes the session in the red as it reveals it has agreed to snap up French communications consultancy I&E SAS.
FTSE 250 Risers
Micro Focus 507p (up 18.5p, 3.79 per cent) Software company continues to move higher, rising for a seventh straight day, with its share price having added over 12 per cent since last week's final results.
Dixons Retail 17.48p (up 0.22p, 1.27 per cent) Electronics chain jumps after Espirito Santo's analysts increase their target price to 25p from 22p while reiterating their "buy" recommendation.
FTSE 250 Fallers
Essar Energy 116p (down 9.8p, 7.79 per cent) Power group slumps following its preliminary results amid fears over how it will fuel its plants, while it reveals it made a $1.14bn pretax loss over the past 15 months.
Regus 83p (down 3.8p, 4.38 per cent) New plans for it to open business centres in motorway services stations fail to stop office provider falling for the fourth consecutive trading session.