Do you have anything documented? Call corporate and explain the situation if you really wanted to move up in that job. Did they have documents that you had to sign implementing the new policies? If so, did you sign them when you came back?
I hate people on a power trip
Documentation as far as what has been going on when management changed. Writing down things that occured help most times, especially in regards to unemployment. If it has to escalate after they fight it (because they just may) they'll be caught lying and not be good for them.
Also, if they made changes to the policy, and you didn't sign agreeing to the policy changes, then that's a technicality. How can they bind you to a policy agreement that you never signed?
All of this is helpful when applying for unemployment. My wife's old job tried to shaft her about policies but she has written documentation where they told her something that was contrary to the policy and standards. Said that she quit but sent her letters stating that she was being terminated. After they found out she was fighting for unemployment, they tried to backtrack and say that she wasn't but it was too late.