Can't Login to Facebook from any computer

Registration date
Saturday September 26, 2015
Last seen
September 26, 2015
I have an account with Facebook. One day, it was simply would not let me log in via laptop. This has been for at least 3 weeks. I am able to log in fine using my iPhone, but can NOT log in from any computer using any internet service. I have used my computers, my friends, my schools, etc. Others can log on to their FB pages on the computers I have tried and can use my computer to log in to their accounts by going to sign-in but I can't. I have no idea who to contact at FB to help me with this issue. Our IT guys say they haven't ever seen anything like this. Any help is appreciated.