VISA's response

Here's the response from askvisacorporate@visa.com to my inquiry regarding how to lodge a complaint against a merchant who has a minimum transaction amount:

Thank you for writing about an issue with a merchant that accepts Visa payment products.

Visa merchants are not permitted to establish minimum/maximum transaction amounts, even on sale items.

If you have experienced this situation, please notify the bank that issued your Visa card. Banks have access to the appropriate Visa rules and regulations as well as to the Notification of Customer Complaint forms which may be used by the bank to document and file merchant complaints.

You can find your banks’ contact information on your credit card statement or on the back of your Visa card.

Thank you for writing.

Visa Webmaster

My original query was:

How do I lodge a complaint against a retailer who won't allow me to charge a purchase under a certain amount of money?

The response is perhaps a bit toothless, but I guess I can always wave the email in their faces . . .