Unfair treatment by Telkom mobile service

I bought a new phone from Telkom in wonderpark mall (pretoria) and paid for the insurance as well and Nov last year the phone was ******. I reported the matter to Telkom and they referred me to Cape Town head Office for which nothing positive came out as they gave me the runaround, till today my phone has not been replaced. The most hurtful thing is that telkom is still deducting the insurance for the phone I am not having, they even increased the premium. Please guys help in this as I have exhausted all of my energy trying to get my phone replaced.