Shocked

I have a loan with nedbank and i just noticed that i was debit twice in a space of 2days .last month i received an email saying that my account has been handed to collections a day after I was debited. when i call them i was told it was just an error on their side, a month later they debit my account twice without a reason what so ever again when i call asking why am I debited twice i get told by a consultant he can't explain it but he will help with reversing the debit order. Honestly, what kind of service is this?