Cancelling of MTN contract

My late wife's data and cellphone contract which is on my name are both going to expire and needs to be cancelled. Went to MTN shop to find out the procedure on how to work. They informed me they can not do that and I must phone 808 as they are the only one which can do that. Super, I am almost DEAF. So if anyone is out there knows besides phoning 808 which is the most unfriendly hard of hearing service in South Africa, going tot MTN shop which is not interesting in helping you or sending 10 emails to different places which each of them goes unanswered have any ideas, contacts or suggestions that make my problem go away can help me, please do so. MTN, service is not a privileged, we pay for it, even the people with disabilities or problems