New scam beware

I recently bought a new phone and the day it gets delivered i have an 800 number calling me saying i need to send my phone back it was shipped in error it wasnt meant for someone else and since the imei number is registered to someone else they can access my data. The number that comes up is the xfinity help number +1 (800) 391-3000. After the 3rd time getting this call i use the xfinity support chat to see if there was an issue. Of course there wasnt. Makes me think this is an inside job from someone at xfinity. How do they know i just ordered a new phone and the day it was to be delivered.