These people are frauds, offering a scam from as claimed Sofia Bulgaria.If you pay by debit card you can claim your money back by contacting the Bank that sent the card. A newish system is in place called Visa Debit Chargeback, many bank staff are unaware of this facility, so poss go to the head office. You have to make your claim for sums that under or over £100 unlike credit cards. You willl not get your money back straight away, It will initially become a 'dispute' in which the claim will be fully investigated by both banks before any money is returned.