Reported a manager who lied about another manager to the GM. After 3 days I got laid off permanently and the GM never talked to me about the incident that I reported then they hired another coworker back the same day I was laid off.

Since March, I was temporarily laid off due to Covid then furlough by July. I got called back to work in August and worked for 5 days. On the third day back at work, I reported an AGM who lied about another AGM to the GM and included the AGMs in the email. The GM never talked to me to discuss this incident but after 3 days, I got laid off permanently and told me that my position will no longer be available due to covid and transitioning to the new management. However, the same day that I got laid off, they hired back a coworker of mine who has been on furlough. They sent her an email stating that she is going to be onboarding for the same position I was hired back. The email was forwarded to me as proof. I wanted to know if I have a case against my previous employer. From what I understand, you cannot hire another employee for the same position that you laid off someone. Please help.