very bad client service

hi mtn are very bad when they change Ts&Cs I was due for upgrade I did an online application at the end of application which was accepted it said I will be charged early upgrade so I sent an email to *** to cancel the application no reply was received & when I got reply it said no cancelation can be done via email so I ph call center and some agents put you to retentions that was about 6 times back ground music and please hold on for next available agent that goes on forever then call get disconnected & some agents give a number *** which is like never going through 51 times now I get handset delivered & pro-rata data & minutes but still I don't know how much to pay. the device is still sealed in its box I'll not open it & stop the future debit and mtn can do what they want this because my son also has a contract with mtn and also due at the same time which he did and there is no early upgrade fee now I want to know how is possible for 1 person to early upgrade & another not to pay is the Ts&Cs only applies to certain people only my personal opinion is that they must get their house in order and waiver my fees or they can take a hike & I'll go to another service provider which im doing now I am a loyal client of mtn for many years never missed a payment & this is the bonus you get shame on you MTN