Over billing and no services met

Since upgrading my contract in May 2015 I have only received my contract benefits (airtime, data and sms) once in May. Also I have been billed for an extra R10 each month, so in essence MTN has ****** R20 directly from my bank account and has indirectly ****** 600 mb data, 400 sms's and 200 anytime call minutes. We have attempted to rectify the issue in shop but were only given a reference and told the issue will be resolved within a week, this was 5 weeks ago. It is impossible to get through to the call center and I have wasted more than an hour on hold, not to mention the time I lost waiting in shop for assistance. Having to use my bank account to top up because of this has also incurred extra costs at my expense. I am truly annoyed, agitated and aggravated.