Paying things twice and fnb not doing anything about it

I paid for petrol the last time . And money was deducted from my account balance but it showed pending on the other side of the fnb app .. few weeks later that amount was deducted again from my money . And i didn't have any funds left in my account . So meaning I have to pay the petrol garage twice plus the fnb fees for insufficient fund. I notify fnb of this issue and I was told a consultant will contact me . Now I got an sms to say the issue is resolved and I should rate the service . My account is still on minus because of this issue and the matter is Not even resolved . And i never got a call from.any fnb consultant.. this is not the 1st time this is happening and am not happy about this cause I always have to pay things twice. I paid the amount is deducted but then few days later it get deducted again. I need this to be fixed before pay day please