Telkom and Mobile Talk poor service

I entered into another cell phone contract with Telkom late November 2020 after being contacted by Mobile Talk. When the device was delivered I was not happy with the device applications etc. I then requested that the contract be canceled with immediate effect and the device was collected on 23 December 2020. In February 2021 I noticed that my account has been billed between Dec-Jan. I contacted Telkom on the matter and they requested proof of courier (Courier IT) waybill which I submitted on 10 February 2021 to Ms. Ayanda Fortunate Tonny. To date, I have been making follow ups and I'm told someone will contact me as they are busy investigating whether the device was indeed collected by the courier company. This is very unprofessional that this matter takes this long while I'm still billed for something I don't have.