Halal Cart

A friend of mine lives near the cart and I visit often, which means I’ve eaten here a few times.
Last time I went I thought the gyros seemed more expensive than I remember — turns out I was right! The guy looked at me, pegged me as a tourist and charged me $ 7 each for two gyros or lamb wraps. Confirmed with the guys running the EXACT same cart the very next day and my friend who lives there that they were only $ 5 ea. When I mentioned it to the guys the next day they denied it, said it must have been a different cart (it wasn’t), etc.
While $ 4 extra is not a ton of money, it irks me that this guy was so flippant about overcharging me. He even took the $ 20 I gave him (for a $ 14 tab), put it in his money box, and kept flipping food without saying anything or giving me any change. When I told him I wanted my change he was like, «Yeah, yeah,» like I was bothering him before he gave it to me!
The food was really yummy, but I’d think twice before going here again which is too bad because some of the other guys who run this cart on other days might be honest folks.