My work uses an X16 with 4 lines, one of which is currently not working. It stays permanently lit and if you try to select it, it hangs up on you instantly and remains lit. The phone number attached to it still transfers to our after hours forwarding call center and they are unable to reverse it. I don't know what caused it as it has been like this since I started working here a few weeks ago but I do know that it was a self install and we have already tried unplugging the server.
Any suggestions? We don't want to contact tech support.

The first thing you need to do is determine if it's in the system or the line. Disconnect the line in question and plug it into a plain old phone to see if it's still bad, if so and you can check it at the DEMARC that's be the next step, but odds are if you disconnect and it's still bad it's a phone company issue. It's either hung up to something or someone or has a short in the line.

Let's see if I have this right: you're down 25% capacity of your phone system, you're dropping calls, and calls are being forwarded off-site inappropriately.

This has been happening for weeks, but you don't want to call support. Anything I missed?

It's not my decision to make, I'm just trying to find an easier solution.

Simple answer.....bite the bullet or put up with it...

I got it figured out but thank you for being the only response that wasn't rude and condescending, justbill.