No service once again

My husband passed away on 26th July 2021. I phoned Cell C to inform them and to cancell his contract. I was told to send his death certificate and ID to [email protected] which I did, I have sent numberous emails to date not even a response. When I phoned then again I was told to leave it as his contract expires soon. I find this extremely unprofessional. I need to cancell this contract