Refusing to pay money taken for airtime purchase but the purchase did not go through, no airtime received.

On the 8th of Feb I bought airtime for a friend of mine who was stranded in the middle of nowhere at night, I bought R20 airtime using the app which did not go through but money was taken from my account, no airtime received. I called the call Centre in the morning I was told to wait for 24hrs, but till today I haven't received my money back, I've called them more than three times, now I've spent R68 on airtime to call them which is more than the R20 they are refusing to credit back into my acc. This is not the first time this has happened, it happens quite alot and that's not the only problem I've had with capitec, they are a selfish bank.I've been a client for more than six years but have had alot to deal with, banking with capitec hasn't been easy as they claim.