They must be getting unlisted cell numbers from carrier.  they called on two lines, both unlisted, one is not used and unknown to anyone except carrier. Maybe they are selling their list to make up for class actions suits against them.  No other way to have got my numbers.

From "Loan Servicing Department"  knew my name, asked me about my home loan amount, knew how much I owe. Asked me about any missed payments, any seconds. Wanted to know my current interest rate. Knew what bank holds my home loan. I made up a loan amount and he told me that was incorrect, then told me the real amount. That's when I started having fun. Once he realized the info I had given was false he hung up.

I don't know how he got my number, it sounded like there were other callers in the background.