Empty promises on refund for card charges on a card I do not own and never have

I lodged a complaint on 22 Feb 2018 about R420.00 that was charged as a card fee - when I contacted them I was told it is for a petrol card - I never ever owned a petrol card before and asked them to cancel and refund my money. I was told the refund would be refunded before 27/02/2018. On 27/02/2018 no refund. When I phoned I was told it will be resolved by end of workday on 27/02/2018. It is now 28/02/2018 and still no refund. If I owed the money to the bank I would have been charged interest on this. Standard Bank has really bad service and I would rather recommend you seek an alternative bank