Cell direct on behalf of cell c

I took a phone with cell c Samsung J5 Prime in June 2017. I claimed in for insurance I Firstly thought its with cell c then they said the only phone covered is my Huawei Y7. I called my bank to ask which company is deducting they said its sell direct. They send me a claim form. They come back stating I claimed late again they said I requested a claim form in 2018 June but they don't have records of my claim. They said my phone can't be covered because I claimed late but I said to the lady by the name of Camille Maccario that there was no contract send to me on how I claim because I was told I must send my phone to cell c for any claims. She tells me that I was able to change banking details, I said yes because my bank helped me to get the contact. I want all my premiums paid back because Cell c repairs is returning my phone not fixed.