Unauthorized deduction

On the 20/07/2020 I received an sms of deduction R3114, 53 which was from avis. Surprisingly I didn't have anything to do with avis by that time. Secondly I don't have an overdraft on my account why FNB aproved it without any overdraft facility on my account? I went to FNB branch at Port Nolloth to reverse it and I filled the form, even today no reversal made by the bank. My is ****** I want it to be returned as soon as possible.