Most cell carriers have a clause in their contracts specifying by what medium they're able to contact you about contract changes (mail, email, phone, etc.) and a time frame in which you're free to leave without penalty (usually 30-45 days). If they don't, however, then unless they put in the "we can do whatever we want" clause (i.e. contract subject to change without notice at sole discretion of [insert carrier name here]...) Then you, in theory, would have the right to sue them for the sum of the early termination fee since they are terminating the agreement early... That is unless they put in the cover our @$$ clause, which basically says they can drop you at any point, for any reason, without notice.
The problem is compounded by the fact that all of these companies put in the mandatory arbitration clause (this is the one that waives your right to a civil trial and instead leaves the decision to a third party of their choice)
Hmm, when I think about it, pretty much every service contract I've read has included one or both of the first two and both of the last two... Yep, we're screwed here in America... So regardless of who's job it is, I think that some regulatory body needs to step in and set up some consumer protections. At the very least, I think that the practice of mandatory arbitration needs to be looked at so that if there is a problem consumers have some sliver of a chance of fighting it.
Cellular service has become a necessity and while they are technically not a monopoly, the major carriers leave very little room for viable competition and should be subject to the same sorts of regulations that other essential service providing monopolies are.