Credit Card Fraud

I've been done again :rolleyes:

Last year my M&S card was used fraudulently and they sorted it out really quickly - cancelled the card, issued a card with a new number.

I paid the card off in full a couple of months ago and wrote to them at the end of last month asking to cancel the account. This month I get a statement and there's a transaction on it for £9.90 to a website (www.ibtis.com I think) which is obviously fraudulent - I've done a bit of searching and it seems this was a website set up just for fraud. I phoned up M&S straight away and I'm really unhappy with how it was dealt with - I felt like I was being interrogated about whether I'd forgotten about the transaction, could it be a subscription I'd set up using the card.... In the end I got put on hold while he took advice on how to deal with it, he came back to me and told me it had been referred to the relevant department - that was it. When I asked what ths meant I was told they'd look into it and see if a retailer had typed a card number in wrong, or if it could be fraud. He didn't offer to have a stop put on the account - I had to request this. I'm really worried that this hasn't been dealt with properly as there was also no mention of the dissociation form (?) that needs to be signed for fraudulent transactions. I was thinking of writing to M&S at the Chester address, but does anyone know if there's a phone number for their fraud department, or a phone number that I can ring and at least talk to someone in this country? Thank you!