CELL CONTRACT - ****************

I feel so violated by Cell C and I am so disillusioned with this company which I used for close if not more than 20 years. I upgraded my daughter and my contracts which included Huawei phones in September 2020 over the phone. I then decided to return the one phone and requested for the contract to be cancelled. However, on trying to renew my contact recently because my old phone is now giving problems I discovered that I am still paying for the phone contract even though I returned the device.. I have an SMS stating that the phone was returned and booked in for assessment on 21/09/2020 +a pic of the van collecting the phone. I have an e-mail enquiring if the contract has been cancelled on 12 Oct 2020. I got busy with life and never realised I am still paying for the full contract. I was under the impression I am only paying for the data, SMS etc. BUT Cell C is refusing to refund my money stating they have no record of the phone being returned. This is ****************, if my money is not returned CellC never get another contract from me or my daughter again. and I will lobby the same from the rest of my family.