Failure/Refusal to refund MY money

I went to Capitec Bank twice this week so that they can refund my Bolt pre authorisation money. As a result of the transaction not showing on my statement (produced by their office). They said they will mot be able to assist me. Even after I showed them proof of the transaction from their banking app. This isn't the first time they do this to me. This bank is a *****. They ***** people's money and claim to be the best bank instead they are the worst bank. I advice people not to use this bank! It's horrible and a headace