Money greedy cellphone dealer

Received a call from vodacom stating there billing charges and plans are changing, i am happy with my current plan and cost, now the problem , they do not offer this package anymore suddenly after a year that i have had my contract and new charges will apply for n similar plan (which obviously will cost more how ironic for them) i asked if there is a plan that wil cost me less with less data and minutes as i don't need as many as i used to or as many as they are offering and i keep getting plan recommendations that cost more , the more i ask for a plan that's either the exact ammount i am paying now or less i keep getting offers that cost more, without my consent if vodacom takes a cent more than what i am paying now (contract bound by the way) i will take legal action against them , so either leave my package as is or if it's not available anymore offer me a package at lower cost with less data and minutes