Extremely irritated

I have had a contract with cell c for last 4 years. and the only way to get a query resolved is by complaining. I was due for an upgrade in May and because they didn't have the device i wanted the consultant that called me for the upgrade suggested that I take a temporary 10gig package that I will be able to change when they have the device i wanted. I agreed to it because it was affordable and would be able to change whenever. Only to find out that she didsomething completely different and I have been complaining about it since 1st of June. And I am being billed an extra R200-R300 every month for something that I didn't even ask for. And I refuse to pay for it. I haven't been able to use my sim card since then and now it's blocked.