worst service I have ever received

Me and my husband went to buy Nike air max for our son yesterday which was Sunday 06.03.2016 the sales guy tells us they are R750.00 then okay we go and pay. After paying only then the guy tells us it's R850.00 said he wasn't aware that the price had gone up, then we decide we want our money back or they must give us with the price that we saw on the box but the manager refused,even getting our cash back we were told there is not enough money inside the till. We ask him what is the way forward he said he doesn't know we stood inside that shop for full 30 minutes if not longer waiting for him to get cash. What I found extremely rude from both of them is that no apology was offered to us they treated us like we are crazy for wanting our money back because of their lack of communication and incompetence. I don't think I ever want to set my foot inside this store ever. Cos at the end of the day according to the Consumer protection Act we suppose to pay the price we saw on the item. They are misleading customer.