Legal Question in Consumer Law in Michigan

Your story doesn't make sense. Yes, store employees can ask you to remain in the store for questionning or while they are waiting for police, such as when they feel a crime has occurred. However, they do not have the right to lock the doors or force you into a room, as that is false imprisonment. I don't see why store employees would go through all the hassle of detaining you (while possibly causing a scene or risking injury), calling the police, go through questioning, and then say "oh we were wrong, my bad, you can go now." What may have happened is that the police told them they were WRONG to lock you in the store and that they should just let you go, regardless of guilt or not, to avoid your retaliation of charges of false imprisonment. Same thing as if a store employee shoved you while trying to detain you - even if you were guilty, they are better off letting you go, instead of facing assault charges. Or, the police told the store employees that there wasn't enough evidence to press charges against you, so the best option at that point was to let you go and instruct you not to return to the store.

However, telling you not to return to the store if you were innocent is inappropriate. An officer wouldn't say that unless there was reason to believe you may have committed a crime or even attempted to shoplift. If you truly did nothing wrong and have nothing to hide, then feel free to shop there. You can't be arrested for trespassing or anything else at a store when you did nothing wrong. While store owners and restaurant owners do have the right to "ban" a person from their premises, there is a reason for it: suspicious or unruly activity, such as a bar fight, etc. If this didn't happen in your situation, then the store has no justification for refusing you entry into their store.