Still received Telekom email despite I've contacted Telus customer service

I'm a current Telus customer, and at first, I received an email notice from "First Choice Credit Services" on June 26, 2025, claiming that I have a certain amount of money uncollected regarding the "settlement" of an already closed account dating back to 2021. I immediately contacted Telus regarding this matter, and I was told that the issue is due to a problem on "Telus's end" and was told "will contact me back in 5 business days". I don't receive any follow-ups from Telus to date.

Now it's July 11, 2025, and I've received another email from "Telekom Law Professional Corporation" with the amount yet to be collected increased.

I have read through another post that has a similar situation to mine, and the OP's credit card score got damaged to an extent that the OP's credit card account was closed. https://forum.telus.com/t5/My-Account-Home-and-Mobility/Telekom-Law-Professional-Corporation/m-p/167450

So what should I do right now? Contact Telus again?