Merchant Caused Mastercard/bank Debit Card To Be Blocked

A merchant in the town where I live, contacted MasterCard and advised their customers at the local store had their MasterCards compromised and then MasterCard sent a list of these costomers to the financial institutions and subsequently blocked those costomer's cards. My bank did not inform me and I found out my name was on the list and my card had been blocked, due to payments set up automatically with my various accountholders being declined and I called the bank to question why my payments were being declined. I believe I know who the merchant was and I had a major issue involving two of their employees and my card recently. Because of the enormity of this issue I want to make a complaint and I've been trying to find out how to obtain the name of the merchant. How do I go about this?