Lack of response / assistance / service

I visited an MTN franchise store to enquire about an early upgrade. I was told that I could upgrade on 1 September 2015. However, my handset is faulty and I cannot use it, therefore requested assistance to apply for an early upgrade. I was referred to the retentions department by either dialing 808 or sending an email. I was also told to visit the walk-in centre at Canal Walk. I have dialed 808 for 2 weeks on a daily basis waiting up to 25 minutes with NO response! I have sent numerous emails only to receive an automated response advising that my query will be attended to within 48 hours. Needless to say 2 weeks have passed and still no response. My last attempt was to visit the walk in centre at Canal Walk only to be told that there is nothing they can do. I am sure that numerous calls would have been made to me had I not paid my account timeously or at all. I have been a customer of MTN for the past 20 years yet they cannot assist me with my request. I have never had to upgrade early but now that I need to, there is no assistance. I have made enquiries with other service providers and will NOT be renewing my contract. A huge inconvenience to me. But in the long run worth it!!