Double billing

I had taken out a contract at telkom for an iPhone on smart 50. Since inception I am being doubled billed for the contract. Upon visiting the store I was told that there were 2 contracts on my name and according to their records they were taken a day apart and one of the numbers had no phone imei number attached. I lodged a cancellation on 5/1/2016 and have not been contacted since regarding the cancellation and refund and this is despite calling the call center and being told there is a 3 day turn around time. I would like feedback and resolution of this before I am double billed again. Case no: ***8