Bad service from Vodacom

I have been a loyal customer for 18 years, but Vodacom's service had deteriorated. Since May last year Vodacom made an error on my account and have been sending me messages saying I am in the arrears. Every month I phone and explain to the consultant, who can seen the problem and says they will credit the amount. It's been a year of phoning and still no joy, really not impressed. How much longer is this going to go on, will not renew my contract at the end of the year. This is not the first time I have had bad service from Vodacom. And the call center is not much help either, you can't hear the consultant with all the noisy in the background. Or they put you through to another department, but cut you off instead. Have no faith that it's every going to be resolved. When I see its Vodacom phoning me to tell me I am in the arrears don't even answer. As I am not in the arrears, just get you're act together and sort out your processes. REALLY NOT IMPRESSED. When will this nightmare every end. Don't even want to phone the call center anymore, so sick of having to explain what is going on.