OP, you were having a conversation with whom?
If (1) you were having a conversation with a coworker and (2) said conversation related to conditions at the job, then your employer could potentially violate Section 7 of the National Labor Relations Act if it takes adverse action against you for engaging in such a conversation.
If the foregoing conditions exist here, then you should consider contacting the General Counsel's Office of the National Labor Relations Board to petition for unfair labor practice charges against your employer.