Problem with 7 eleven?

ok so today i went to 7 eleven with my brother, we had 5 dollars and a 5 dollar gift card. we wanted to see how much we had on the card so we asked the lady that was behind the counter and with the very little english she knew she told us "i dont know how to do this" . I was like okay.. then why are you working here to my self of course, so i buy a slurpie and use the gift card to see how much we found out there was 5 dollars and so i bought a slurpee for 2.06 so we had 2.94. so my brother gets 2 taquitos for 2 dollars and a beef jerky stick for 1 dollar, and some hot cheetos. So we go up and give her the stuff, she puts it in and he swipes the card using the 2.94. then i ask if i can add some skittles. and so she looks at me very rudely and gives me a snicker of annoyment, which is not good workmenship, so i just ignore it, anyways with her unknowing of anything to do behind a cash register she redoes the whole thing. so we scan the card again but since it was already used there was no more money, so she says sorry i dont know how to do this youll have to take something away, Obviously the Skittles and the hot cheetos are not 5 dollars by its self, and he PAID for the beef jerky and the taquitos with his gift card, so what ended up happening was she praticaly stole our 3 dollars from the Gift card and we still didnt get everything we wanted. So i know its a measley 3 dollars but its the fact of her not knowing what to do, being rude with us, not knowing barely any english, taking our money, and us not getting our full order. Does 7 eleven have a manager or somewhere i can report this lady?