MTN customer service is the worst

Since 6 May I have been trying to change my contract -online and new App didn't work, went into V&A Waterfront store and was told it was changed but it wasn't. Called and got through to their USELESS OUTSOURCED retentions company who offered me a great deal because I am a 'long standing valued (!?)customer 'and 3 weeks later is still hasn't been implemented despite receiving my contract from them on Monday this week. I have called numerous times, emailed and contacted their customer contact via FaceBook and keep being apologized to and told I will be contacted. But nothing!