AT&T BBB, FTC AT&T practiced unfair business and got support from BBB and FTC Sparta New Jersey

My Internet account with AT&T was closed back in 2017. Three AT&T representatives confirmed that I have "0" balance, no further charges should be paid by me. A year later when a mortgage company ran my credit report I found out that AT&T reported my closed account to the collections due to $107 unpaid balance (I had no AT&T Internet as this provider did not serve the area where I lived!), and now my mortgage company will have to charge me extra $1,662.50 because there was a drop in credit score by 60 point. I called AT&T to try to make nessesary adjustments to avoid being overcharged, no one cared there. I ended up paying $1,662.50 to the mortgage company. Then I asked BBB to help me to get a refund from AT&T. BBB closed my case without any refund. I emailed to FTC and received a general email with a link to the Internet article 10 ways to avoid fraud over internet. When it became normal in this country for such companies as BBB and FTC to support an unfair prictice of large corporations as AT&T?