They call, but won't talk

Called 2 times in one day. Claimed to be from the treasury. Tried to repeat his name, but said the wrong name

Called twice, when I called back the call would not go through, called the third time and I answered. Wrote down the information so I could check up on it. Supervisors name was Christine Mill. Wanted me to call 929–9 99–18462 verify a $7000 grant. Just called back to tell me I needed to call her supervisor now.

Keeps calling and hanging up - naturally, the number is disconnected - how to stop this?

Said I needed $250. For the taxes.. His name was Jacob White