Capitec...what a nightmare to deal with

What an awful bank to deal with. I booked online flights on the 29 Oct. The transaction went thru and my balance decreased. On the 3 Nov I received an sms showing the same transaction going thru again.and all funds were taken from my account. I was left with a zero balance I immediately called the bank and was told that there was nothing they could do as the airline put the transaction thru for a 2nd time. I printed a bank statement which clearly shows the transaction going thru and another one pending therefore my account had a zero balance. I went into the pinelands branch and I was told the same. Even though the pending transaction was dated 29 Oct and the actual transaction 3 Nov. My question to them was why would the transaction of the 29th still be sitting there if it was cleared on the 3rd and why was all the money taken from my account. Every person at capitec gives a different explanation which makes no sense. I am struggling to just get this hold removed. It' seems no one there knows what they are doing. Or maybe this is capitecs business model. Where they put holds on people's accounts and they cannot access their funds whilst capitec is gaining interest somewhere else on all this money. Disgusting. And they claim to serve the lower income earners