A police force paid out £3,500 in compensation to a woman after she complained about the way a rape was investigated.
The 38-year-old woman launched legal proceedings against Cambridgeshire Police after she claimed they failed to investigate her attack properly.
A force spokeswoman said a letter of apology was sent to the woman and compensation was paid to her in an out-of-court settlement.
She said one officer was disciplined for failing "to investigate a matter expeditiously".
She said another was given words of warning after it was found that record-keeping was "wanting".
The spokeswoman said: "Cambridgeshire Constabulary made no admission of liability in this case.
"However, a letter of apology was issued which apologised for any distress or anxiety caused and we can confirm that £3,500 was paid in an out-of-court settlement.
"The civil claim followed from a complaint that had been made by the claimant over an allegation of sexual assault.
"The record-keeping of one officer was found to be wanting and another officer was found to have failed to investigate a matter expeditiously. The first officer received words of advice and the second a superintendent's written warning."
The woman, who suffers from bipolar disorder, contacted police in December 2005 but when she called again in February 2006 she discovered officers had not looked into her claim, said her lawyer Harriet Wistrich.
The woman employed Ms Wistrich's services and launched legal action, claiming the force's lack of action had breached her human rights.
"She was unwell when she first contacted police and a few months later, when she was better, she contacted them again and found out they had done nothing and had left the file under a number of papers on a desk," said Ms Wistrich.
The solicitor said that vital CCTV evidence showing the attacker and his victim at a cash point after the incident had been destroyed during the time lapse.
"People who are particularly vulnerable are often seen as more difficult cases and sometimes the police seem to be lazy and not bother investigating because it is harder to get a conviction," said Ms Wistrich.
She added: "Police should take seriously any rape complaints."
Campaigners said a high number of rapes reported by vulnerable people end up being "no crimed".
"This case shows that rape cases are not being treated with the priority and professionalism that they deserve," said Sharon Smee, justice policy officer of the Fawcett Society.
"Research shows that victims with a vulnerability are more likely to have their cases 'no crimed'.
"There is a desperate need for training with initial responses in rape investigations."
Earlier this year the Fawcett Society released figures suggesting that Cambridgeshire Constabulary had one of the lowest rates for rape in England and Wales.
The figures, which cover the period of 2006 to 2007, show only 3.1 per cent of rape claims to the force ended in a conviction.
The lowest rate of conviction was in Dorset, where only 1.6 per cent of rapes ended in a successful conviction. The national average was only 7 per cent.