I have been on Ebay for a few years now and luckily have managed to wind my way through the many pitfalls. Lots of people are all claiming that Ebay and Paypal are ripping them off, well this guide is to help UK Ebayers help themselves.
First important point Ebay and Paypal charge for the services they provide, they are therefore trading within the UK if you have a compalint about illegal activity and they don't reimburse you as stated in their policies, then report them to your local Trading Standards agency. (Enough complaints and Ebay will end up with a case officer and investigation)
Second Point - before PayPal was allowed to set up and hold peopless bank account & credit card details, and provide what is in effect a financial transaction service, they had to register in the UK and agree to be regulated by the Financial Services Authortity.
In each case you should direct your complaints to the appropriate authority.
Final Point - if they rip you off, take them to the small claims court, you can submit a claim yourself and do not have to pay for a lawyer as you can do it all yourself.
Remember you are only a victim if you let yourself be.
Best of Luck