Mweb after sales service

I have been with Mweb for app 18 months now.My internet access has been almost non existent for the last 3 months.Its almost impossible to get hold of someone for after sales service.Eventually got hold of someone who told me that they do not have efficient details on my account to assist me??There was no details needed to debit me and take my money for the past year and some months????I have to use mobile data to email them when I am paying for a service which I cant use???Getting hold of them over the phone almost non existant.I just want to cancel my account with them and even that is impossible??