Vodacom will increase your contract price whenever they want

Vodacom are greedy and ripping us.. I have a contract with Vodacom and I also have a contract with Telkom..as of today Vodacom added an additional R20 to my contract and when I enquire about this I was told that it’s a 5% increase due to inflation,and Vodacom said that 5% increase only applies to contracts and not prepaid … but on my Telkom contract there is no such thing they said if took a contract for (I.e 300 pm) it will be like that until my contract ends.. so basically Vodacom can increase their prices during your contract period whenever they want… what’s funny is that on their website they are still offering the same device with the same amount that I took it for and not with an additional R20.. so I’m guessing this their stunt to lure customers in and after 6 month increase the price… THIS IS GREED