Allstate Insurance: David Howard

I have never been so mistreated by a business. I was a customer of Allstate for a year while in Chicago and had no issues with them. When I moved down here to buy a house, I reached out to the closest agent, in this case David Howard, and asked for a quote. I did not choose to go with Allstate because I had better insurance offered through my employer.
Yet, I then received an email notification that my policy had been charged even though I had only asked for a quote and had never given him any information about my broker, which is required to start a policy on a house. I immediately emailed back (and still have the email as proof) stating that I had never requested a policy and to immediately remove it. A month later, I get a call from Allstate billing stating I have a bill even though I had received no further communication via email or mail, so I had assumed things had been taken care of. Really pissed off, I explained that this David Howard was clearly illegally trying to bill me to increase his commissions and they assured me that it would be taken off. Then, just today, I get a bill from a collection agency about the exact same bill, again after having received no communication whatsoever from Allstate regarding a balance.
So now, my credit score is being affected because this asshole billed me and failed to rectify the situation. Then Allstate Billing also failed to rectify the situation. Finally, I called his office today and spoke to someone who assured me they would speak to David and get it taken care of and I have still not heard back. It’s unbelievable to me that people can be such scum just to make a buck and for my credit score to get messed is beyond infuriating as mine was over 800. Who knows if I can even get that fixed.