[drewcrawford]

You are talking nonsense. The "right to free speech" in the United States has developed over hundreds of years of jurisprudence. It is impossible to summarize here but for starters involves not only Congress but also states (Gitlow v NY) and even private parties (Snyder v. Phelps). I don't mean to suggest it is arbitrarily broad but it is certainly much broader than to say it is "only" the text of the first amendment.

Secondly, "intimidation" carries a very specific legal meaning, for example here's the Montana statute [0]:

    (1) A person commits the offense of intimidation when, with the purpose to cause another to perform or to omit the performance of any act, the person communicates to another, under circumstances that reasonably tend to produce a fear that it will be carried out, a threat to perform without lawful authority any of the following acts: 

     (a) inflict physical harm on the person threatened or any other person; 
     (b) subject any person to physical confinement or restraint; or 
     (c) commit any felony. 

Unless GRSecurity is threatening to break your legs, kidnap you, or rob your store, they are not intimidating you.

What we are talking about is refusing to do business with you, which is very legal. There are some exceptions, such as if the basis for that refusal is due to your race/sex, or if GRSecurity is a cartel, or if they are refusing in order to obstruct an investigation into some other illegal activity, but I'm not aware of those kinds of facts here.

[0] http://leg.mt.gov/bills/mca/45/5/45-5-203.htm