Make a dozen copies of the receipt that shows the surcharge and report them!

I'd also go back to the DQ and talk to the manager and ask for a refund.

Found a local gas station around here charges a 25 cent surcharge if you pay by cc.  I found this out when it showed up on the receipt from inside (vs from the pump).  They also coded the surcharge as "grocery" so there was an additional 5% taxed added to the bill.

I choose not to go to that gas station anymore.