Divide Insurance Agency

I had a relationship with an agent in this shop for about a year and a half. At first things were fine — our venues, public places, frequently required special certifications and changes, and, like any other insurance broker, they were understanding about this and took care of alterations quickly and competently.
As time went by, the agent we primarily dealt with seemed incredibly annoyed when the government agencies we worked with asked for changes of address, additional certifications, etc. — to the point of ignoring communication, sending us the same (incorrect) forms over and over, refusing to call or respond to emails, etc.
Now, please understand; I and my government partners were not being capricious in presenting these changes. I was as unhappy as the agent was with the additional time burden, but these were alterations required by city, county, and state government agencies, law, and regulation — without which the charity events I produced could not occur. I doubt she expected her client to cease business simply because it annoyed her, or perhaps she was just unhappy with the charities we were raising money for. Perhaps she did. I’m not sure, and I won’t speculate as to her motivation.
The final straw came when the agent forwarded («accidentally,» but more likely purposively passive-​aggressively) an entire email thread between herself and the insurer itself, in which she told the insurer how much the client (my company) irritated and annoyed her, how happy that she wasn’t going to allow us to renew with her, etc.; this damaged our reputation and was certainly legally actionable, but I’m chalking it up to utter incompetence rather than malicious intent to damage my business and reputation with the insurer itself, who has told me they value our business and want to keep my company as a client.
I already forwarded that email thread to the State Department of Insurance, as I couldn’t believe that a professional insurance broker could possibly behave that way. I was an utterly astounding experience, and by far the worst customer service I have ever had the misfortune of being party to.