This same question gets askes several times each year. The correct answer is always the same: you have to call (by standard voice telephone) the Frontier “Retentions” or “Loyalty” group at 800-921-8101 option 2 or 951-209-1474. This is the same group of people who handle voice phone line issues. They do not have an online chat capability, but they do have access to all your previous chat sessions.
The results you get depend on the person you talk to. If you are told you have to cancel your current account and switch to a different provider for at least 30 days (this happened to me once quite a few years ago) just say “I’ll consider doing that”, hang up, and call back later .
The people in that group do have the ability to lower your monthly rate, but it is not clear to me what determines exactly what they will do. Over the past few years I’ve had them lower my rate twice. Right now I"m at 500/500 + phone for about $65/mo, and that’s close enough to the “new customer” price that I’m not going to bother calling them again.