FNB NO ASSISTANCE

I hate that I have to write on hello petwr to get FNB's attention. My account was settled last week and I was still debited, I cannot get through to anyone at FNB and they keep referring me to the app which is proving to be useless. THE MESSAGING DOES NOT WORK. I need the debit order reversed ASAP. my account also keeps going nto a negative with no explanation why, I cant see transactions that would warrant this. I am so irritated with FNB I am considering another bank.