getting down graded

Firstly I have been with Iburst for a very long time... but always get socking service.<br> I have upgraded my contract from a 1MB to a 2MG modem... I have even paid for it since it has gone dead on me.... now they have upgraded my contract again but send me a 1MB modem. Why must I pay R599 PM for a down graded option... I want this resolved urgently and I'm picking up very poor network. I need this sorted out... or I will take matters to my attorney