Bad service from FNB

My fiancé reported a ***** transaction on his mother's account on the 03.01.2020 and to date have not received any feed back and any attempt to call FNB on *** has not been successful. Call not answered or he waited 10 minutes. The first date of a deduction done on her account was 27/11/2019 R608.11, 04/12/2019 R700.85, 13/12/2019 R609.34, 24/12/2019 588.94 and 31/12/2019 R673.54. all these transactions was confirmed by the person he spoke to on the phone. He would appreciate it if he could be assisted in this matter.