Harassment from Telkom Mobile

I have 2 cellular contracts with Telkom Mobile which have both reached the end of their terms but I do not want to upgrade at this point in time. Telkom sales agents keep on phoning me to upgrade and I keep having to repeat myself. I easily get 10 calls from Telkom daily and its driving me crazy. I have blocked a lot of numbers but still it continues. I have posted twice on their Facebook account and still they keep on harassing me to upgrade my contracts. I have now contacted the Ombudsman to lodge a formal complaint. Next step is to get legal advise to get a court order or something to stop them from calling me.