Unfair price increase

I got an email saying my contract price will it increase on 1 April by 5%. On my last contract I was paying R149 per gig, the price per gig dropped to R85. I asked if my monthly contract would decrease, I was told no as I signed a contract and committed to pay R149 for 24 months. For enough the contract was signed. Now when I ask why my contract is increasing now I am told vodacom can has the right . Besides committing to a contract for 24 months. Only when it's an increase it will change but not a decrease. A contract bundled with sms that no one uses. Un the next few days bot my wife and I will migrate out packages to the lowest top up available and ride out the contract till it expires and then change providers. We will also be canceling our fibre during the week and get a cheaper provider with better benefits. This week R3000 will be off your books . Hope the 5% is worth it. And still increase prices but still no customer service over 40 min on hold screens shots were taken. Ps for R52 a month standard bank gives me R220 airtime and data per card swipe. My dual sim phone will make the calls and will receive from vodacom downgraded package till I can migrate my number