Billing and Bad Service

Neotel keep on ignoring me and they are billing me over R300 instead of monthly instalment of R179. I sent dozen of emails and their call center does not function properly. I call trough their call center with no success, but before I used to get through. They promise to sort out the billing since there was a problem when they gave me wrong product at first. Im really tired with the service they are providing. They are wasting my money with their product that I don't even use because is poor.