Poor service from 135

I have always experienced horrible customer service from MTN call center both prepaid and post paid, I called the customer service number 135 because of the issue I'm having with my number *** I have been receiving countless calls from different numbers claiming that I just called them, and I have to advise that its a wrong number, the call centre has been givimg me the code ##002# code to erase call diverts but that code is not working, I spoke to Abongwa who said he was based in cape town call center, he said he couldn't help because his system is not responding just after he made me hold on the line for a good 5minutes,when I requested him to put me through to his supervisor he gave me attitude and dropped the line, I called again and I spoke to Aviwe who also put me on hold and dropped my call, I called again and spoke to Nothando I explained my issue and that the code provided is not working she said they cannot cancel the diverts for me on their side and will log a SR for me, upon me holding for the ref number she dropped the call. My last call made was to a gentleman called sphelele who went out of his way to assist me but still couldn't get the issue resolved. I have never dropped the call with a smile on my face after speaking to mtn call center agents, no amount of professionalism is portrayed by them or even going out of their way to assist they are very quick to give you ussd codes without checking on the system what the problem could be or taking your number for that matter. I have a contract with mtn for acc number BA***, its a cellphone and wifi, my cellphone is due for termination next year June and I have decided to cancel because of the poor service I always received from the call center.