MTN LIMIT SUSPENSION ONE DAY AFTER UPGRADE

I have upgraded yesterday, 2015/05/02 to an MTNSky package. I have 3 contracts with MTN for work purposes. I have upgraded to MTNSky package due to me being on the phone a lot. This morning I received an sms stating that my account has been suspended due to my limit being reached on the account. My other 2 phones are still working, bearing in mind my spouse has the one phone and my mother the other. I have the MTNSky phone which is the iPhone 6. I am not happy with the service as I had problems due to their system when I did the upgrade and sat in the branch for more than 2 hours. Now, my line is blocked. I utilize my phone for work, therefore I could loose income should I not have a phone. I have never missed an MTN payment. Now I am getting penalized for upgrading???? I need my line suspension lifted immediately. I feel I cannot actually pay for a service that I am unable to utilize. When I phone 808 you hold for half an hour plus, and the call gets dropped anyway so the 808 service is JUST AS USELESS. MTN needs to sharpen up their game. I am ready for a fight- I WILL NOT PAY SUBSCRIPTIONS IF I DO NOT HAVE USE OF THEM_ FULL STOP. MTN is becoming a nightmare network- Pity....