I'm still a PPL working my way up the ladder, but here are my opinions:
This is a disgrace. You had a decision to make and chose to err on the side of safety. That is commendable. I don't believe you should even be held accountable for such a decision, but to be reprimanded and disciplined is unthinkable. Have these people never flown an airplane? You contacted the manufacturer, and they affirmed that you made the correct decision. If the CP has chosen to suspend you, HE is remiss in his duties. I dare suggest that you inform the company in writing that if any further action is taken against you, you will be forced to consider legal action against them, and remind them that the press would just love to hear a story like this. With the recent public awareness of aviation safety, it'll be all over the news.
I would also suggest that you send a letter to your FSDO, as the CP is a required position at a carrier, with a FAR defined role. This is in clear violation of said role. You are in a position to file an official complaint, and that should get the FAA to start an investigation.
On a more positive note, maybe it's a blessing. It never looks good to be fired, but do you really want to fly for a company with this sort of attitude? I doubt a future employee will penalize you for your actions. Going against the grain is one thing. What you did was observe AFM limitations and demonstrate your competence as a commander.