Didn't answer, but called back the number. They answered "Discover" and proceeded to ask for account number and my phone no. I said I would call back the number on my Discover card and they insisted they were Discover Card. I called the valid Discover number and they had not called, nor did they need to call me.
This number, 801-902-3152 , is part of a social engineering scam.
It is used in conjunction with 800-347-3723 to try to get personal and financial information from the vicitm by posing as collection agency and fraud prevention numbers from Discover.
Please do not fall for this scam.
Discover Card collections department. Will call persistently if you haven't been paying your Discover bill.