Poor customer service

My husband opened a CUM account and visited the Greenacres branch today. He bought a cooler box using the R300 off R900 voucher. It was marked R1299 and he paid R999. He also bought a shoe that was on sale from R1799 to R1399. He couldn't use a voucher as it was already marked down by R400. He then decided to buy a set of battery operated lights marked R550 and was told by the cashier/salesperson that she would make an exception and allow him to use his R200 off R600 voucher seeing as though he would've had spent almost R3000 on one visit. When the manager came to authorize the transaction he refused to override the system and make the exception. My husband left without the lights and is inclined towards returning the cooler box and shoe in light of the poor customer service.