Cancel contract

I have a problem with MTN I took the contract with MTN is not even. 1 month. I wan to cancel the contract but if I phone. On 135. They said u can do it in store. And. If. Go to store. They said phone. On 135. And do it ther and finally I. Spoke to store manager he said if u will cancel the contract u will pay. Fined which is. R5300. And that is phone. Worth. Is. R5000