Checkers Boksburg stinking service

Paid for my bill at checkers liquor 7 Jeremy Kark's Rd, Eveleigh, Boksburg, using my cellphone and they said that I did not pay because it didn't show on their side. I showed them the transaction on my bank statement but they insisted that I pay again. A senior staff kabelo monyaki @ 14:01 was asked to come help at the till without greeting me and said that I had to pay again. What passed me off is that said this has happened a number of times and they have done nothing to correct that. What if I didn't have any other money and the account went over the limit. Who pays for the charges then? Please pay back my money