MTN customer service is pathetic

I am in my 3rd upgrade term and until now the service was exceptional. Im now due for an upgrade, did the online upgrade, receivedan sms saying the application is approved and didnt hear anything. I then called in to find out what the delay was, only to find out that MTN has outsourced their application and upgrades to Mondo and that I should call Mondo to find out. I did so and was advised that the package i selected was out of stock and they cannot say when the stock will arrive. I then went in to a MTN who confirmed they had stock, but couldnt process my upgrade because it was locked by Mondo. This now becomes my problem as I need to contact mondo and send a request to cancel the upgrade request. It is now 7 days and im yet to receive any news. Why are MTN subscribers being held up by a company we have no contract or agreement with ? I have to make follow ups each time. Why cant MTN follow up and keep me as the customer happy ?