Double billed

I received a double bill for my device upgrade, upon calling the call centre to rectify I was told by the agent that that's just how it is. I then asked to speak to the manager who then promised to call back, I am still waiting for the call back days later.

I have been upgrading for many years and in all the years I have never been double charged for a device in the first month it makes no sense, especially since I was contacted by Telkom Mobile for the upgrade.

Firstly on the upgrade it was not explained to me that I would be double billed, I would not have proceeded with the upgrade. Secondly very poor customer service Telkom! I want the double bill to be reversed and only one months device charge to be allocated to my account.