Lack of adequate information / Product Knowledge in MTN stores and Call centre. Soo disappointed

I got a message that I am due for an upgrade on my 30th Month of my current MTN mobile contract, On getting to the store I was told that I will be charged for the other 6 months because its an early upgrade- MTN call Centre Said there wont be any charges but the MTN Stores in 4ways mall refuse to upgrade me if I don't accept the, +- R2500 early upgrade charge , I explained and called the Call centre again but no one seems to be sure what the process. I am so disappointed with lack of adequate information with MTN