I appreciate all the help guys. I managed to figure out the issue today, and as I thought it was absurdly basic/stupid. Apparently my company has a third telephone line that nobody bothered to inform me existed. I was going off the assumption that the line I was using must be the correct one via process of elimination.

Long story short I decided to make absolutely sure there was a dial-tone on the line I assumed to be the correct one by plugging our phone system into it briefly (I didn't see an off-hook option on the machine, although theoretically it would have had a line and I would have still had the same problem). Sure enough there was, but I decided to make sure it worked by calling my cell...that's when I saw the number of our third phone line...from there I deduced the problem.

All this time I had been trying to test the fax by sending a fax to itself...after I finally plugged it into the proper line I finally got a busy signal and conformed it was working properly by sending a fax to it via the web.

I need to stop assuming issues are more grandiose than they actually are haha.