******* into a 24month contract!!

I was ******* into a 24month contract by Summer mobile! I was due for an upgrade with MTN in September 2017. I was late to upgrade and I received a call from "mtn" telling me I can do an upgrade over the phone. I declined and said I was not ready for an upgrade as yet and when I am ready I will go to a MTN shop. I was never told that i was speaking to summer mobile not MTN. I was told ok since I'm passed my due upgrade I can reduce my monthly rate instead of paying the current contract rate. I asked the "MTN" consultant clearly can I upgrade at anytime. The answer was yes anytime. I have tried to now upgrade at a mtn shop and I was told on the system that it is recorded month to month but I can only upgrade in Dec 2019. MTN could not assist me as this was a Summer mobile deal. I am so upset that I was not told who was assisting me and was duped into a 24mth contract!!!!