Absa bad service, deducting money(unauthorized bal see)

Good day everyone, my complaint is concerning absa bank, now iv got a cheque account, for more than a year, now since a few months ago, on my statement says unauthorized bal see, so it went from - 100 to now at - R560, now when my salary is paid then their goes the R560, i was told it was a something about credit, buti can't afford it, if absa doesn't do anything, ill move to another bank, whit my salary, absa is taking money every month and thats not even my account fee. So im very angry, i will leave absa if they don't stop charging unauthorized see bal on my account. Don't come whit nonsense, sorry we can't do anything, its either you help me whit this or ill go to another bank. It wasn't even explained when i opened this account.