at will employment

After reporting my managers for violating company "code of ethics" I told the division president I was worried about losing my job and he promised me I wouldn't lose my job nor would there be any retialation by my managers for coming forward and that he would make sure of it. He did in fact in front of me tell both managers they we're not to retaliate against me and that I would not be going anywhere. Well it took over a year but they finaly we're able to force me to resign or take a demotion and sign a written warning letter admitting to doing things that we're fabricated. When I asked my new manager how the division president could allow this to happen, he simply said that if you say a rose stinks enough times, after awhile everyone will be saying that the rose really does smell like shit! His way of telling me that the other two managers had been talking smack about me for the last year and the division president started believing I was screwing up. My question is, does the division presidents promise that I wouldn't lose my job cancel out an at will employment contract?

Is this promise in writing? I doubt it so believe me they will say that this was never promised and you will have an extremely difficult time proving that this was promised. It would not change your at-will employment status.

Your right, his promise was verbal only. thank you for your timely response.