Possible ***** on my account but no assistance

I have had a debit order going off in my account u don't know where it comes from. The debit order is written Vodacom but Vodacom doesn't know about it and the bank says it's not their problem. So I'm really frustrated of this amount going off my account that I don't know about. So if my bank can't protect me from unauthorised access on my account who will help me