I got fired but was not given a reason.

I am a black male and received a call from my employer that the store I was assigned tot did not want me there. When asked why, I was told the manager at the store said i didn't listen to him. I have only had 1 conversation with any of the managers there, and fixed the issue immediately. The other reason I was give was that I was on my phone. Well, my job is to advertise Smart TV's and 1 of the main selling points is that it can be controlled by the phone. So yes, he is correct, i was using my phone as it is part of my job. i have never had a conversation with any of the managers, except once, and that was too tell me I was not wearing the correct pants. I was never welcomed there or made too feel like part of the team.