Pep - Durban - Workshop

Yesterday, i done shopping at pep. I swiped the first time it declined. I swiped again and it went through. When i got home i went through my bank statement and saw i was charged not once by twice for my goods. So i phoned pep, spoke to one of the managers on duty and she told me that if a purchase is declined it wouldn't go through at all and that the fault is with my bank, capitec and that no one was over with their money. So because of purchasing goods and being overcharged, i must do all the running around to get my money back. That's a bit unfair. Who's going to compensate me for my time and money for running back and forth to find the problem? Who?