Mtn upgrade - *****ing my airtime, not using the minutes

I upgraded my contract in November, and with the upgrade I was suppose to receive 400min, once the upgrade was done my minutes carried over showing 1573 minutes in total, it did not stipulate whether it is Mtn to Mtn or anytime minutes. Then I got a message saying that I have finished my minutes and when I did a balance it still shows that I have 1573 minutes, when I call an MTN number I am using up my airtime and not the minutes. I had to recharge twice already and still my balance shows as such. I have escalated this, reference numbers SR *** SR *** REQ *** REQ ***

Mpho Mooney from your Simmonds Street branch has been awesome in helping me and keeping me up-to-date however she is not receiving the support from her Organization.

PLEASE HELP