I assumed the issues were specific to the Mitel PBX. Testing with a cell phone allows me to see if the number we are dialing is having issues that could impact the PBX(assuming I can complete the call at all). I still think something is wrong, in that it shouldn't be dialing the speed call at all, however I think there is also something wrong with the number we are trying to dial.
So far, all of the phones on the PBX are behaving the same way, dialing the speed call instead of the 8 or 12 digit number dialed(these numbers are listed in a previous comment), both on and off hook. When I then deleted the speed call and then dialing the 8 or 12 digit number, I got an INVALID instead, whether dialing on or off hook.