Charging device fee outside of contract term

I have tried the formal route, that did not work. So now I will try the social media route. I have been charged for two months outside of the contract term for device charges.

My contract expired in June yet I am still being charged for the device. I complained and the call centre individual said that she would credit the amount and cancel the fee. This has still not been done.

Personally, I am thinking of cancelling this service. Paying over R1,500 a month and it pretty much goes to data costs. It's ridiculous.