Bad customer service

Dear peter ... I am not happy with PEP stores the one in Carlton centre this is my second bad experience with the store first it was the cashier giving me attitude when l wanted to do an exchange reported that to manager BT recently l was buying tissue oil and hand lotion my bill was 35rand so l swiped then cashier said it declined asked her to swipe again she told me that their having a problem with fnb cards if she swipe again u can find out that she have charged twice so l had to check online banking as fnb doesn't send message wen staff is less than 100 so l saw that it did went thru l asked her if its like this wht shld we do coz it have gone thru on my side she said they can only refund if l bring my bank statement l told her l do stay in the cbd so if it means l have to take taxi to bring that proof for just 35rand who is goin to pay my taxi money so l asked the manager how do you handle such situation because it doesn't matter how much it is but the bottom line its my money so as l was still in shop same issue happened to another customer so lsaid to them clearly yr speed point or system have an error why don't you fix this imagine how many customers are you going to be dealing with regarding the same situation so ntombi the manager said she will call me as soon she get hold of their finance department until now am waiting for her call so am going to go with the proof that they said they need and please @Pep stores l also want my money back and taxi money to go there when stupid system error ...please peter kindly assist and take this to PEP stores