Negative credit report att decides after almost 5 years that I owe money on a house I moved from in 2019. New widow victim

My husband just passed last November. Iam off on my own just starting out with credit since all of our credit was together. I k ow big mistake   Anyways I just happen to run a credit report on myself last November 2021. To my surprise there is a negative entry from credence resource. After 2 hours with barely English speaking foreign help and being transferred multiple times I was told that I owe att 171.00 on a house I moved from in 2019 and sold in 2020. I never got any…… emails, letters or communications whatsoever. 
the answer was I never cancelled service. Why would I want service on a home I no longer living in? When did they decide finally that I moved? Why now after almost 5 years? I filed a complaint with every governing agency I could think of and plan to let the world know

what they did to me. I am queen of small claims court being that I had a 2 year legal education and have never walked away not receiving money if it not for recent surgery I would take that action again and I still might do so.