It happened to me last night again! I was registering my hockey team (Ahhh yes, hockey season is back!) and the card transaction didn't go through and I had to call in and clarify things up. Huge lineup behind me, embarrassing. I called CIBC and told them that this is the 3rd time this happens to me using the same "merchant". They did the same thing for the past 2 years and even though I called and told them that I'll be doing this transaction for the foreseeable future, they still blocked me . I told them that they better shape up and if this happens again I will be canceling my card.