Isn’t firing me for sting I feel discriminated against and that I’m reportung it to EEOC illegal?

I worked for a company owned by two brother since June 2017. I resigned for another opportunity 10/18..on 10/20 I was asked to return by ONE of the owners with promises of a promotion soon. I accepted and started back work on 10/21. When I walked into work on 10/22 the OTHER owner asked me”what was I doing there”.(he asked me this same question the night before wen he saw I had returned and I have him the same answer) I said,”your brother rehired me”. He said”we don’t need you , I need to clock out and leave”. I called the owner who rehired me and he said he didn’t know what was going on but he would call me when he found out. That night he called me and said his brother said he told me to leave because someone told him I was saying things about him and his brother(which was totally false). I told him I think the reason was he didn’t tell his brother that he was rehiring me because he needed me and his brother wedding agree with him bringing me back. He told me he would find out the detail and get back to me. The next morning 10/23 I sent a text and email to the owner letting him know I feel his brother discriminating against me because I’m a woman an I’d he could look into the issue. Since that text/email I was ignored from that point on. After 2 days of no responses I emailed/text him saying im filing a complaint with the EEOC because of he discriminations.(which I did).A week later I received a separation notice in the mail dated for the 26th as the day of separation .i filed for unemployment and was denied .we had an appeals heari and he told them under oath and was recorded saying I wasn’t fired wen his brother told me “we don’t need u,clock out and leave”. He said I was suspended pending an investigation regarding hear say. He said he didn’t even get to start or finish the investigation because I started sending him emails claiming discrimination and the EEOC, he said after I sent those emails he showed them to his team and they advised him to terminate my employment. So I wasn’t fired until I complained of discrimination and told him about my filing of the EEIC complaint. Isn’t that illegal?