I filed a Better Business Bureau complaint because they kept insisting that it was a bank issue. All I asked was that I be re-imbursed for the overdraft fee caused by the way they were running the card.
The response was as follows:
Ms.
So basically, it's VISA merchant policy to authorize for tips over 20%, which I tend to do when the service is excellent (I like to round up to round numbers). So, I guess the bad service is that none of their managers in store know this policy (since all of them told me it was my bank), and that they don't have any notices about this up, or even just at tiny line printed on their credit card holders when they drop off
ETA: (because I forgot) Their letter also entirely ignored my actual complaint, which happened in early February, and instead went into detail about the first incident, which I specified was an inconvenience, but did not cost me anything in fees.