Verbally confronted and questioned aggressively in Krogers, do I have a case?

I visited my previous Kroger store location, where I had worked prior to being transferred. While inside the store, I was verbally confronted and questioned aggressively by the administrative assistant, who asked why I was there. This interaction felt hostile and unprovoked. I immediately reported the incident to my union representative. However, I felt that my concerns were dismissed. I was told not to worry about it and was advised not to write a statement, which made me feel as though my side of the situation was not being taken seriously. The following day, I was suspended based on allegations made by the same administrative assistant, who claimed that I had a gun and that I cursed at her. These allegations are completely false. During a separate interview with my union representative, the administrative assistant contradicted her own claims by stating, “I didn’t hear what he said; I couldn’t make out what he was saying.” Additionally, management was unable to provide any video evidence showing me with a gun. The footage they reviewed actually supports my statement and shows that I did not have a weapon. Given these facts, I believe these accusations are unfounded.