Call blocker might be of some help. Also don't pick up on numbers you do not recognize, or where there are caller IDs that seem odd. Or where there is no caller ID. There’s no way to stop the calls from being initiated.
I reported this number to the FCC. My husband is a telecommunications engineer, he and I have worked in telecom for over 20 years. Whenever you receive a call like this, report it to the FCC, especially if the caller makes any threat. If threats are made against you, then the crime becomes extortion and that's a federal crime.
The caller IDs himself as being from the US Treasury and they want to "give" me $7000 no strings attached. This is now the 2nd call and this time I told him I'm not interested in whatever kind of scam they are trying to sell. I then told him to have a nice Fuc*in' day and hung up.