Reversal Request

Such terrible service I received from FNB.. I called in Monday requesting for assistance in reversing an incorrect amount that went off my account. They advised that since it does not appear on my debit orders I need to complete a reversal form. I completed the form on the same day ( Monday) and emailed it to FNB. I got an automated response advising that my request will take 5 working days. Today I called and spoke to Darren, whose line was extremely bad due to his network. He advised that the request would take 7-30 working days..This time frame is 1stly not the one I got when I sent the form and even the lady that sent me the form said 3-5 working days.. I need this to be resolved as per the initial time frame. Such a big bank needs to have proper SLA in place. This is nonsense