Refund credit just vanished

I bought a Tefal pan on promotion, however the price at the till point was still the full price and I was charged accordingly. I disputed it and the R100 was supposed to have been credited back to my credit card and to date nothing and I bought the pan weeks ago. The lady insisted to refund to my card and now my money is just gone and forgotten. I am a regular and buy almost all appliances through them. Hillfox branch is responsible for this and I feel like crawling back to Game stores due to this