Trying to Upgrade for over 4 weeks now

We have been trying to upgrade now for the last 4 weeks and they are just unable to help us because if its not the system its the printer, if its not the printer its the biometrics failing, if its not that then we are blocked on the MTN system to upgrade and the latest excuse is we upgraded to long ago this doesn't make sense at all, I have been a client of MTN for over 10 years now and never missed a payment this has been the worst service ever, and no one gives me the same answers, nor do they supply a rout to follow to sort this out we just got of the phone with a call centre agent and his words where "I can't do anything they have to sort it out in the store" Mtn is Useless.