Trying to cancel a business land line

We have bee trying to cancel a business landline for months. Telkom is by far the worst service provider in this country. We are being pushed from pillar to post with no luck. All we want to do is cancel a line. They have the worst contact centre agents we keep giving you the wrong numbers to assist. We have received no help from them and the service keeps accumulating fees each month which we have to pay. They literally will not help you cancel.