A mother's good deed backfired when her car was clamped as she delivered items to a charity shop.
Dawn Dowuona-Hyde was dropping off her children's old clothes and toys at the British Heart Foundation shop, in Hounslow High Street, when clampers struck on May 24.
The mum-of-two, who lives in Isleworth, this week called for tighter regulations on clamping firms as she battles to overturn the 'extortionate' fine.
"I thought I was doing a good turn and it's ended up costing me £340," said the 40-year-old social worker.
"I pleaded with the clampers to release the car but they just stood there smirking and said I'd have to pay.
"I gave in after a while, despite the extortionate amount, because I felt quite intimidated by these burly men.
"I can't believe how little regulation there is for clamping firms, that basically have a licence to print money."
Mrs Dowuona-Hyde parked in Prince Regent Road, behind the charity store, and had only been inside for a couple of minutes when she realised her mistake.
The clampers, from Regional Clamping Services, were busy tightening the screws as she rushed out.
But they still demanded a £170 call-out charge on top of the £120 release fee and £50 VAT.
They told her if she didn't cough up on the spot, in cash, her car would be towed away and she would face an additional charge of £35-aday.
There was no response from Regional Clamping Services to our enquiries.
Clamping firms are regulated by the Security Industry Authority, which requires clampers to be licensed, but has no control over the fees charged.
In Scotland, wheel clamping on private land has been outlawed since 1992.