Brewer & Brewer, PLLC called my job – is that even allowed?

I have been getting calls from Brewer & Brewer, PLLC for a few weeks now. I ignored most of them because I assumed it was spam. Then yesterday they called my actual workplace and asked to speak with me. My coworker took the message and now everyone is looking at me sideways. I am so embarrassed.

I called them back and they said they are a law firm collecting a debt. I told them not to call my job again. The person on the phone said they were just verifying employment. Still felt wrong to me. I have no idea if this debt is even mine or if it is too old to collect on.

I found this page that explains some of my rights and what Brewer & Brewer, PLLC can and cannot do: https://consumerlawfirmcenter.com/brewer-brewer-pllc-calling/

Apparently they can verify employment but cannot discuss my debt at work or keep calling there. I am thinking about sending a cease-and-desist letter. Has anyone else had them call your job? Did you end up settling or getting a lawyer? I just want the calls to stop. Thanks for reading.