I have a personal account with the coop bank, which I've been using to trade Bitcoins on localbitcoins.com. I recently had a trade of £1250, for about 7BTC. The buyer paid into my coop bank account, & the escrow was released for the bitcoins.
A few days later I received an email from the coop's fraud department, saying the buyer's bank had claimed that the buyer hadn't received their Bitcoins, & they wanted the payment reversed. The coop froze my account (which had a balance of £250) & requested "proof of entitlement".
I obtained screen-shots of the trade, proving the