Cell C fiber forcefully charging more

Cell C is just going from bad to worse. On Tuesday 18th May. I received an sms stating that SADV is migrating to Vumatel and the prices of fiber will change in from 1st of June so they are charging me a whopping extra R200 and only giving me a 10 days notice. Plus if I want to cancel I must pay for the charges of installation nd so on that were given to me for free if I keep my contract for 2 years. I emailed them and today a consultant called me I explained to him my point of view that I'm not in breach of contract while they r because I signed my contract with Cell C not with SADV plus they are giving such short notice all he could say is if I cancel I must pay for the charges if I don't then I accept to pay the R799 so they r basically forcing me to pay which im mot happy with. Also we checked and found out that they are charging people in other areas much cheaper than my area.