Cancellation not processed

24 month contract for Samsung Tab ended. Emailed cancellation request. Still being billed for the Tablet. Called the contact centre and was told by Thenjiwe that the account has not been cancelled. And that i am being charged higher rates for out of contract services. I use to pay R199 for the tablet. They now charge me over R500. Are you nuts??? more than double the amount. I then ask for a manager and get placed on a long hold only to be told that there was none available. I asked for a call back. 24 hours later still no response. Its obvious when a service provider is in the wrong the hide away from the facts.