My parents had to resort to this to break out of their contract with AT&T when mobile service went to absolute shit following the 4g rollout. Repeated trips to the local store were met with them waving vaguely at the service map and refusing to do a site survey, calls to corporate were stonewalled. After 6 months of this, they called the AG. It was resolved within a week and AT&T let them out of the contract without penalties.

It is a damn shame that people have to go nuclear like this, but sometimes it is the only option.