bad customer service

I recently had a problem with FNB which I also posted on Hello Peter about the bank doing a double debit transaction without my knowledge. Then on the same day that I posted on Hello Peter, I received a response within the same day and I was impressed. Now its been almost two weeks later and there loan department is yet to contact me so that I can make arrangements for there mistake. So on the 13/05/2019 I called them twice and both times they said they going to email and try and contact the person that is handling my account to get back to me,but I am still waiting on that call unfortunately. Then on the 13/05/2019 I get sms again stating that my debit order for my loan has not been paid due to no funds in my account,obviously this would happen because my debit was supposed to go off every fortnight on a Thursday and the debit went off on a Monday. Also the fact that I am now nearly waiting two weeks on a refund that they are apparently going to give. The REf:- ********** and the person handling this is Tsepo, I don't know his last name.