Telkom prolonging my contract after cancellation

I have a cellphone contract with Telkom mobile. My 24 month period has expired. I was told that the contract is not automatically cancelled after the contract period lapses. I then went into a Telkom store in Ballito,KZN. I completed the contract cancellation form on the 25th of April. I had to call in myself 2 weeks later to get feedback. Someone had not sent my form to the correct department. I don't see how that is my problem. My contract is still not cancelled, even though have done all that is requested for cancellation. My suspicion is that Telkom is just prolonging the period of the contract for their own gain, they do everything to get you onto a contract and make it difficult for you to cancel once your period is up. I am not impressed with this service, especially because this my second complaint on Hellopeter for the same service provider. I definitely do not wish to upgrade or renew my contract for this kind of service. Today they called me to urge me to upgrade, yet no one can call me regarding my cancellation request.