I'd like to know this, too... For my own account of course, not TheMayor00's. 😉
I'm in a similar situation. Turned in my old modem yesterday morning, was told I'd get an email when it's processed, but didn't get a time frame for when that would happen, and I didn't ask for one. Assumed it would only take a couple of hours.
Obviously I assumed wrong...
Still not updated on my account page this morning so I called customer service.
He said it shows as being turned in back on 6/4/20, when I turned it in at the store, and that the only modem currently showing on my account is the one I actually have here at home. He said he recently turned one in as well and it took a week or two for his account web page to update.
So, there's hope, I guess...
FWIW, resetting a device to factory defaults will not "disconnect" it from being provisioned to / attached to an account. It's not related. It's the account data in the backend database that determines that.