business internet disconnect nightmare

First and foremost, I am a residence. In fact, I am the sole house on the street. The cable was brought into my street which is mostly industry.  I was told at that time I could sign on at 69.95 per month for a two year contract for business internet at the time or pay $3000 later to have the cable brought to my residence.  I signed the contract.  The contract expired in June of 2017.  In September of 2017, I tried to no avail to switch to residential service as I am a residence;  I have never been a business.  This process has on my end taken about 20 hours on the phone back and forth with residential and business only to be given the run around.Beginning in August of 2017,  I probably left 10 messages with business internet service because I was unable to access my email when service was migrated in August 2017.  That is when I recalled my contract ended expired and I won't be charged an early termination fee.  Each time I am on the phone it is a 30 to 1 hour nightmare explaining my issue.  I continue to get a bill even though I have switched servce to Frontier residential service.  My outstanding bill is almost $300.  This is ridiculous. I hope someone has a direct contact because I want to be done with comcast business forever!  I don't want them to send comcast business related mail each week either.  Please advise.