I think the one good thing is:- our banks and credit card people always seem to get in touch with us when there is a problem with the card. I had a call last month that someone was trying to take £1.00 from my account. I was told this is sometimes a test to see if more money can be taken. However, it was just a company I had signed up to, making a test payment.
I was really glad my card people where on the ball, as they always seem to be.
I am sure some techy person will give you some advice here Karen, but it just shows how on the ball your card company are to warn you and stop any payment.