debit orders reversal

their service is bad, I paid certain Company via Eft and they debited my account I went to Fnb branch to reverse it because I have already paid, the lady asked me if I have FNB APP then she said I must login then she asked me to hand her my phone then she just did whatever she did without showing me anything then she said she reversed it,I haven't received any message confirming reversal nor the processing of it, when I call they say due to covic19 they can't help me and they hang-up on me, I tried secure chat several times with no luck from 21 May 2020 till now nothing is said or done.