terrible customer service

on Saturday i went to PEP, when i got to the cashier they swiped my bank card, the money went off my bank account but the cashier told me that it was declined on their side, i left with no stuff and no money. i have tried the whole morning to get hold of someone at PEP to help me and i am getting no assistance. according to my bank it will take 30 days for the money to reverse, this is absolutely ridiculous. i will not wait a month for my money. this was my daughters birthday present that i was trying to buy and now i must explain to her why she doesn't get a birthday present??????