The disgusting incident went down July 15 in Stafford, Virginia where a Verizon employee recorded this man named Robert Colonna going berserk. Colonna was so pissed about something not working -- and its cost -- that he hurled a loogie at the closed door, and then started dropping n-bombs as he screamed at the workers.

The staffer who posted the video explained it this way ... "[He] assaulted me before entering store throwing phones inside store then picking them up leaving the store claiming he had something else for us. I IMMEDIATELY locked the door behind him."

The employee, who is heard on the phone with either cops or corporate, goes on to say, "He used racial slurs and spit at me. I know his name is Robert. Robert initially pulled up to the store in a company truck making a hard stop in front of [the] store before jumping out and assaulting me while I was holding the door for an elderly man. He was only charged with Disorderly conduct. When police arrived I asked about assault charges. Robert stated he tripped before he hit me..true but his intentions before he tripped was to hit me I believe...as you can see what I mean."