This kind of thing makes me really angry. I'll check my statements aswell, just in case.
I worked for a small business some time ago and we dealt with another BIG publisher who had the habit of deducting £1000 from the credit cards of those who had advertised with them and refunding it the next day. No harm you may think, but just think of the interest the publisher earned for having several thousand lots of £1000 for 24hrs at a time... So low and yet very hard to pin down to being fraudulent and not just an admin error. I do hope that Magicalia are not playing the same trick.