ho help recieved from mtn branch in wonderpark

I opened a contract in wonderpark 19 months ago and paid my contract even though expensive compared to others in the market. I had decided to cancel my contract, pay before it comes to an end, I went to the same branch in wonderpark. The rude male(tshwana/Sotho) did even if try wait for me to finish my request for canceling the contract, he rudely told me i should "dial 135, my balances will show there". I did that the whole of yesterday, nothing, i still don't know how to cancel the contract. Now more than ever i want nothing to do with MTN and its poor, disrespectful service. I want to close the account tomorrow. The same branch has been sending SMSes, telling that i am eligible for contract renewal, really.