Originally Posted by Majuki

I have to wonder how many merchants just expect people to say, "Forget it." over a small transaction, which in aggregate ends up netting them a lot of profit. Now is all cases I proactively say, "Charge <local currency>." In the case of Spain, I might pull out the hoja de reclamaciones trump card, which usually forces merchant cooperation. If they say, "We're out of complaint forms." then you know they're lying. A merchant is required to have them, and a customer can call the police to make sure the complaint form is received and filled out. Sometimes there's a bit of a standoff, but in the end the merchant will always capitulate.

My current best practice is that I always allow for enough time to resolve these matters. I'm not saying you took the wrong action here either. Back in 2011 I probably wouldn't have even realized I had gotten ripped off, but reading stories like this infuriates me.