Empty promises and useless complaints management

I was promised a refund on my card requests as compensation for my petrol for driving back to the store for an error that's was not mine. I got a new card then there was a system error and my card was not activated. I advised that i cannot afford to go back to rectify the error, can they deliver a working card instead as it was your system error so why did i have to suffer for it and since you couldn't deliver the card the arrangement was that i will be refunded for the new card transaction as compensation for my petrol. Then i went to the back and sorted the card and was told all refunds will be done by close of business the following day. Three days no refunds were done and instead i was charged twice for the card transaction. Then i contacted i raised the complaint on monday and i was told both refund are being processed. And it was agreed that both transactions will be reversed as compensation. Only one transaction was reversed and the one is still outstanding, when i raise this with the complaints department all they do is just close my query without proper investigation. My query was closed 3 or 4 times with no investigation. What do i need to do to get my refund sorted?

Regards Palesa