Poor customer service

I have an FNB account and I realised that there’s money that was mysteriously transferred from my easy account and easy zero to my savings account on the 25th of December and all of the sudden i was on overdraft with an amount of R2792 on my easy account which I don’t understand, I was informed that my query has been escalated to the relevant department they will be in touch till today I haven’t received any feedback. Their service is pathetic!