Cellphone contract

I am eileen. I am a pensioner and my husband was very sick. In approximatly august 2017 i cancelled his vodacom account due to the fact that he was very ill. Up untill today i muat still pay an amount of more then R600 and my husband passed away. I only receive the pension that he left for me. He had cancer. The nesseccery documents was emailed to vodacom headoffice to stop the account but they are still taking my money. I want my money to be refunded and the contract to be stopped.