Bad Customer Service

I am contract customer for more than 10 years now, with 4 numbers under my contract and 1 is due for an upgrade. I have called MTN direct on 135 more than 30 times and my contract application is in pending. I have gone to the store about 3 times in Sandton/Rivonia to update the required details. Please mind you my account is paid up and up to date. Their agents keep telling different stories, (update your documents, your credit limit is low, application is in pending,application is approved wait for delivery, the whole of march different stories). The worst service I have ever heard with MTN and I can't even get through to a supervisor or manager. It's so embarrassing for a loyal customer. I have never been sent from pillar to post like this. I am paying my account and it's up to date and I have gone to submit all required documents in store, I don't know their problem is.