Cellphone Account Upgrade Nightmare

My wife and I have operated multiple MTN accounts for the last 20-odd years. The accounts have been in my wife's name since inception. For the past month we have been trying to upgrade/renew 2 of these accounts, and get sent from pillar to post. Although the new upgrades would cost around R300 per month more (in total) we were informed that the upgrades were declined due to a "Credit Verification failure". We requested to move the accounts into my name, or that I sign surety on my wife's account - and we don't even get a response. In spite of the failed credit verification, MTN is happy to continue operating the accounts on a month-to-month basis! Customer Service - it simply doesn't exist at MTN