Poorest service

I contacted my bank via their online app chat to get clarity on bds absa transactions but instead was assisted by an agent who approached my query with sarcasm more than anything, this is even after I explained to him what had transpired, he still could not explain & still do not understand how a transaction that went through successfully on one day can lead to bds insufficient charges on the next and to have your bank tell you to just avoid having insufficient funds, whilst you explain that this was not the case.I am very disappointed by the poor level of service I just experienced from a bank I trust.