Annoying lack of customer service!

The service is very very bad. We have been trying to cancel a sim only contract for data. We have driven 3 times to the Richards Bay store. They just won’t help us. They are permanently offline. Which is not a good sign for a service provider. They say we have to use the phone service they answer the phone but the minute we ask to speak to cancellation they cut us off or the Phone just rings. How are we meant to get this contract cancelled. I would like to get a contact for the CEO maybe we will get some joy from there.