Price Increase

I just received an email from Vodacom stating that they've decided to increase the subscription fee on my contract.<br> When I signed the contract, I agreed to a predetermined monthly fee. They cannot just increase it whenever it suits them.<br> If you want to increase my subscription fee, you need to add value to my package by, for example, increasing my data bundle.<br> I've been a Vodacom customer for around 18 years, but if you decide to proceed with this increase, I will seriously reconsider my options as each of my contracts come up for renewal.