Thank you for your question. I'm sorry to hear about this situation, as it seems unfair.
In actuality, they cannot hold you at all, as they are not law enforcement officers (they are only security guards). Thus, this situation might be what is legally known as "false imprisonment
." However, them telling you that you cannot leave is not the same as them forcing you to stay there. Unless they locked you in a room and physically prevented you from trying to leave, then no claim for false imprisonment will arise.
The next issue we need to address here is what potential effects it can have on your employment. Since you are not directly employed by Macy's, but work for a contractor, it is only the contractor (your boss) that can terminate you. From what you've told me so far, there has not been any indication from your boss that your job is in danger. The single legal issue that could arise out of this would be a claim against the security guards for Tortious Interference with a Contractual Relationship. They knew you were not a Macy's employee
. They also knew that you did not know the rule regarding removal of merchandise from the store. Thus, if they file a false report with your employer, they could be liable to you for damages under this theory of law.
Finally, we need to address any potential criminal charges that might arise out of this situation. Theft requires proof of intent and actual completion of the crime. You stepping out into the mall with merchandise and then immediately returning to the store, given the circumstances, does not qualify as theft under the Florida Penal Code.
In the end, you have essentially been the victim of some very over zealous security guards. I suggest that you work with your boss to file a complaint for this and see if Macy's management will discipline the security guards for their ridiculous behavior.
Please let me know if you need further information or wish to talk about this situation further.