Who called from 3150000031

Wanted to know who owns this phone number.

Getting a call from a man saying he is from the US government grants department trying to get me to give him information so he can give me $7800.

I also received a call 7/19/16 from the same number various times offer the same grant amount. Told them to verify through correspondence. He hung up.

I answered my son's phone, his number is on the do not call list.
I couldn't understand the caller as his middle eastern accent was so strong, although he was speaking English.
When I called the number back I got a recording that the number was not in service.

Do not trust these people they took me for all the money I had! Feeling extremely stopped right about now.