Nedbank Poor Customer service

I am a Nedbank Current client, for around 5 years now they have been debiting my account for a policy on my Credit card that i never knew off, it's taking them over 3 weeks with no feedback on proof that i did sign on voicelog that i took the product from them, all i get from a Lady that works with Policy's is that they waiting on the Branch to send feedback and the only time i get feedback is when i send a mail to them asking for feedback, that's the only time a get a return mail from them saying the same OLD news, waiting for feedback from the Branch, the thing is, I am a exsisting client and this is becoming so frustrating that a Bank can take your hard earened money via debit order, but when you want Proof, all they can say is that they waiting for it from the Branch, But strange enough, when i intianlly Phoned the Branch before i log a call with the Call centre, the lady from the Branch said she could not find anything on file relating to my query, it's now gone into the Fourth week and still no response from them, and i am they client that still banks with them. So sad that Banks actually treat us this way,