Blah. Did some research, it looks like a merchant would really have to anger me for me to report them. Maza wouldn't qualify. One link gives the addresses one could report violations. The only good news from that link is that one supposedly can call Amex at 1-800-297-1234 (U.S.) to report violations.

I did find something interesting on the visa site here


Minimum Purchase

Visa merchants are not permitted to establish minimum transaction amounts, even on sale items. They also are not permitted to charge you a fee when you want to use your Visa card.

If you run into a problem like this with a merchant, please notify the financial institution that issued you your Visa card. These institutions have access to the appropriate Visa rules and regulations and can help you document and file your complaint. You'll find their address and/or telephone number on your Visa statement. Their telephone number may also appear on the back of the card itself.

--end quote--

I guess we can all just call our credit card companies to report violators. We all know how this goes. It's a pain, but if enough people did it...