Money paid to my card not available to me

I purchased an item with my card from another bank which expired by the time I decided to return the item. The cost was R2200. The store was not able to give me the cash obviously, and had to refund the money to a card immediately. I asked them to pay it to my credit card which had an installment of 300 due and I thought that would cover the installment and I could use the rest. Little did I know ABSA would take my money and not allow me to use it! That is MY money in the card and I will not rest until I am able to use it. They say that because it was a refund it is not available to me. But the item was never purchased with their card in the first place. I will become your worst nightmare if my money is not made available to me.