Serious lack of efficiency of Mtn network

After failing to pay on time my lines all but one (which has a dual sim card) were suspended. After payment my lines were reconnected but the above mentioned line was suspended. This all happened 2 weeks ago and it is my business number. I have contacted Mtn several times. The different responses: Your sim is Rica-barred/ it is a network problem/the line is activated on our side/the sim is cancelled. And the last response: no network settings for this number! I have been using this number for a couple of years now. Since I have upgraded a month ago, I lost out on 30 GB of data I could have used in these 2 weeks and have to use another phone and purchase prepaid data daily. Every consultant promised that the line will be activated within 24 hours but still nothing. I am frustrated and don’t know what to do. If I had known that this would happen I would have cancelled my contract with Mtn rather than upgrading it. Please help!