Horrible service and my money was taken but I got no food.

I went to KFC Eldorado park today wanting to buy food for around R300. I used vouchers that I always use at various KFC outlets, at the drive through they couldn't access it. Then I went inside and they said it was invalid and I just had redeemed them before I left the house. They said that they will call me back after they spoke to that division and guess what....they never called me. I don't have the food or the vouchers anymore. This is such bad service as I told them that o always use these and have used them before at the very store. So where is my money now because now the made them to be as used but I can't use them somewhere else as they punched it in their system. I either want my vouchers back to buy at another KFC or they must give me the food.