For 11/11, the Visa rate for 1950.00 MAD was 178.52 USD. In reality, this was 5.28% higher than Visa's rate for that transaction. The only benefit is to the merchant in getting a percentage of the rip off.

Does the bottom of your receipt say signature not required (or the equivalent in French)? If so, you could add that the merchant had control of your card and the credit card terminal for the duration of the transaction and refused to void this transaction to reprocess in local currency.