Account Collections Issue

I’ve been dealing with the same situation recently. Telus sent my file to collections agency when I had NO outstanding bills from them, it was from a closed account in 2022. I recently found out about the collections agency when I was checking my credit report and the collections were flagged,  I have been calling Telus customer service only to find out about 4 different collection agencies that has my information. Telus has even confirmed that I don’t owe them anything but they won’t give me a proof to show the collections agency that has been harassing me by phone and email unless I pay for the copies of the previous bill from a closed account. It’s all so ridiculous. Telus has caused me so much stress that no one deserves to deal with and they don’t even help you to sort the mess they created. Any tips or advice on how I should proceed with this? Thanks in advance