Cancel my contract!

I'd like to cancel my contract, I've been going back and forth with emails and phones calls regarding my upgrade. Never once received a proper resolution or response. Emails asking for my details and to then direct my query was received several times and having to repeat myself with the exact same information. After almost 15 emails being sent and still not on MTN consultant has assisted me fully! Do you guys prefer to just have a bad name? My contract expires in June this year and I will gladly make sure that I won't be paying any further until my contract is canceled. I pay for terrible service and badly trained staff! I've went to the extent of writing reviews, sending emails and still nothing has been noticed. I will be canceling my debit order as of June