Blocking is a wasted effort. I have at least 75 of these calls in my call log and they have never used a number more than once. The numbers are spoofed. They also frequently use my area code and exchange for these spoofed numbers which is really funny because I moved last year and kept my cell number. I am 1200 miles from where the exchange is assigned so it is quite comical when they call about my electric bill. Don't answer numbers that you don't recognize. Simple.