I want to know which collections agency my old debt was sent to

Hi everyone,

this is my first post and it comes after hours on the phone with ATT. I hope someone can help...

This is the issue:

• I cancelled my old phone number in 2014 and paid all expenses tied to it
• I moved to Europe for work
• I recently came back to the USA and got a new number/account
• Today, I mistakenly logged in my old cancelled account and I saw that I had an outstanding amount of 17$ that was sent to collections agency.
• No one in ATT can access my old account or understand where my debt was sent

I would like to know which collections agency it was sent to and delete this issue from my credit report.

Can anyone help?

Thanks in advance.

Eddie