FAILURE TO ASSIST WITH CONTRACT CANCELATION

I am trying to cancel a month to month cell phone contract for my husband who passed away and because I can't remember security questions from 15 years ago I am told I have failed the security questions. I have spoken to five people and get the same answer, when I ask which questions I have answered incorrectly I am told that the manual does not allow them to give me that information. I do not receive accounts from Cell C. I see that the contract on my husbands phone was changed to include SMS's and data which he did not even know how to use. My experience with Cell C has been very traumatic and I will never recommend them to anyone again.