Cancelation

I contacted the company where I took out my Neotel contract in order to cancel our contract as we are moving to Jeffreysbay and unfortunately Neotel does not cover that area. They suggested I send an email to retentions@neotel, which I have done. I still havent received any feedback from retentions, I tried to call the call centre number, but no answer. Please assist me to cancel this contract