Telkom is useless

The last 2 years I have had struggles with my Telkom Mobile account where they blocked my account because of miss allocations on my Telkom account I want to cancel all of my Telkom lines now due to this as it is pointless not being able to use your account and you have paid your account I think they are in breach of their contract with me how do I go about to cancel all of my contracts as they cannot assist me when I phone their customer service number.