I can’t reach anyone about outstanding bala

I was a Telus customer until March 2023 (moved out of AB). My bank is telling me that an outstanding debt to Telus is showing on my credit score. I can’t figure out what it was for (I had home, mobility and security services). I no longer have access to the Telus app, and when I tried calling I was on the phone on hold for 2 hours and then was disconnected. I need to reach someone in the accounts or billing department to figure out what this is. Does anyone have an email or even a postal address?