Is cell phone (MTN) providers *****ing our money?

I have received an SMS yesterday to tell me our SMS's will only valid for 30 day as from 15 April 2021. I feel they are *****ing our money. I buy SMS's for my alarms system's at all my premises. It is convenient and because the SMS's did not expire. I do not always have accesses to internet or cell phone signals to buy new SMS's ever month. Apart from that, I feel if you bought something it's yours. You can't take my blanket, that I bought, at the end of winter and says it has expired! So why can they take your data and SMS's. *******ion and *****ing for people at it's best! Don't know if it's the same with other providers, but I am thinking of cancelling all my contracts (total of 9) with them.