Lack of service/ ITC listing

Absolutely disappointed with the lack of service at MTN. About six months ago I had liasied with the call center to have my contact terminated as I was moving to a new service provider. This instruction was not executed and as such it was listed on my ITC report. Furthermore I must now pay close to R2000 for a service that I never received nor made use off. I did not receive any calls nor emails pertaining to my subscription and hence was under the belief that my instruction was executed. My bank account had no unpaids from MTN. This is inexcusable. What is the justification for not carrying out a simple request from a client? Why should I be out of pocket because of this?