After visiting the dentist and paying income tax, trying to find a decent nanny must rate as one of life's more disagreeable experiences. I have been on the nanny hunt since 1988 and have had six so far, three good and three bad, but the failures far outweigh the successes.

I've tried all the standard ways: advertising in The Lady (a faxless, bottomless source of girls who do not speak English, girls who say they want the job but never turn up for the interview, girls who would rather be doing anything rather than looking after a baby).

I've tried word-of-mouth recommendations, sharing with other families, the Nanny Times and, last, least and definitely worst, I've tried the nanny agency.

I rang an agency because my nanny, who had been growing larger by the day, suddenly disappeared, never to be seen again. (Was she pregnant? Had she burst?) In despair I telephoned an agency in south-east London.

'Help]' I wept. 'My nanny left this morning. I have three deadlines and two small children. I need a replacement now. . .'

'Don't worry,' they soothingly replied. 'Leave it with us. . .'

And to start with, they couldn't have been more helpful. A charming girl turned up; calm, competent and cheerful, she organised my children without fuss or bother.

I was hooked. Even the fee - around pounds 100 - I had paid to join the agency to procure this gorgeous girl seemed reasonable. But, as it swiftly became apparent, this was just the first in a series of bills, each larger than the last.

The first fee entitled me to a daily stand-in nanny until the agency found a permanent one. When they failed to do this, they suggested a temp. I agreed. The temp arrived, another charming girl whom my son loved from the start. She was accompanied by a bill for pounds 141.

When I wondered why my initial payment to secure the first temp did not cover the second one - and bear in mind you are also paying the nanny's salary as well as the agency - the agency replied: 'Oh, but if you don't pay this fee, you'll get a different nanny each day. This way you get the same nanny each day.'

But after four weeks, another bill arrived, ushered in by a note that suggested that in order to keep this temporary nanny, I must pay further weekly instalments.

It doesn't take a great deal of brain power to work out that it pays the agency not to find you a permanent nanny for as long as possible. I rang again to find out what was happening.

'We're working very hard on your case,' they soothed. A further week went by; another bill appeared and then I had a phone call.

'We've found two delightful girls,' said a voice, 'who I think will suit you very well. They'll ring you today to arrange an interview.'

Nothing happened. I asked what had become of these delightful girls.

'Maybe they decided they weren't interested,' said the same voice. 'Sometimes, well, you know. . .these girls. . .'

Well, I do know these girls, and that was precisely why I was paying an agency to weed them out for me.

Another week, another bill and then, another phone call.

'A brilliant girl,' the voice enthused. 'I used her myself. She is just perfect and very interested in your job. . .'

Nothing. Not a whisper, not a peep, not even a phone call to say 'sorry, I'm not coming'.

Then the agency had a brainwave: 'Perhaps the temp would like the job?'

I put it to the temp, the temp said yes and lo and behold. . .another bill from the agency, this time for pounds 282. 'Why?' I queried.

'Well' they said complacently. 'Your temp nanny has become a permanent nanny.'

'But, listen' I said. 'I had no option but to offer her the job. You failed to supply any other girls and what's more I was the one who asked her if she'd like to work for us.'

'She's now a permanent nanny,' they intoned implacably, 'and under our terms and conditions. . .'

This agency, with its sweet, helpful exterior, and its greedy, iron-clad heart, was proposing to take more than pounds 500 off me for supplying one temp and making three phonecalls.

But what really makes me continue to seethe with fury was the letter from this leech-like outfit replying to one I had sent saying I was unhappy with the service they had provided, and objecting to the size of the final bill.

By return came not an apology or an explanation, but a threat of court action if the bill were not paid by the following day.

'If we were in the West End,' they had added smugly at the end of this missive, 'we would be even more expensive.'

(Photograph omitted)