EEE WHAT KIND OF THEFT IS THIS

I was on iphone6s plus on my choice 100 open contract, then they upgrade dada me to 200 what what claiming there is more data duh, now I have a phone which is a piece of trash as my data run out way faster than my 1gig open contract. I call 4 people then I run out od airtime. I am sorry but the whole concept of having a contract phone and not being able to use it its ****, besides I am I even sure that they load all the stuff they claim to do coz honestly since I forcefully went on this new package I have one problem after the other data finishing not being able to call. after being with mtn for so long the problems I have are enough for me to reconsider my contract with them, what the hell