Minimum purchase price

BP At Roodekop Phumula is exploiting a poor community. How can a BP have a rule that one must buy for R30 rands if they want to use a card. The company must not save on bank charges at the expense of the community. The staff saying it’s the rules they work under, honestly it’s unacceptable. Can this be resolved. No entity must dictate how much one must spend before they use a card facility. No sign on displaced to show this stupid rule