Words and phrases definitely have meanings in contract law, established by precident. They are not always what the layman would presume they mean however.
> "T-Mobile will never change the price you pay for your T-Mobile One plan," the company said in a pledge that enticed many people to switch plans or even switch from another carrier to T-Mobile.
I don't think it's reasonable to use anything but regular definitions for the words in that particular quote.
Rather, they are pulling this off a completely different way:
> "We are not raising the price of any of our plans; we are moving you to a newer plan with more benefits at a different cost."
So the price of the service is not changing during the reasonable lifetime of the service nor the lifetime of the consumer. Rather, the service is no longer being offered.
And this is probably permitted in the fine print of the offer. They did not just make this up in their marketing department without at least some consideration of the ways they could escape from it.
But to try to ditch their responsibility with a technicality is so scummy. I don't have T-Mobile, and with that one line of corp speak I never will
We seem to have reached a point where there is effectively no place you can get decent customer service as an ordinary consumer. It's either, have enough money to sue the crap out of companies, or shut your mouth and endure.
Decades of demonization of regulations has led to a point where the Govt's ability to enforce them is effectively null. With the regulators out of the picture, T-Mobile knows the only real recourse you have is the courts and that a vanishingly small percentage of customers will take that path.