Livetracker Cancellation still being billed

I was emailed by Vodacom indicating that they are changing suppliers and I had the option to cancel or sign a new contract, I opted for the cancellation option in April 2015 until today I am still paying off this contract even though I am on a new tracker. I was told that the credit will reflect on my account and it is still not reflecting on my account. This is utter *******. Very quick to increase my premiums but utterly useless in refunding my money.