how can i block incoming numbers in my iphone 5
I am getting calls from numbers that are trying to sell something and the first thing they say Hello MIKE .That is BS and here are the numbers they are calling from:866-396-5767 And 239-443-4992 Cape Cpral.FL and deferent numbers starting with area code 818 San Fernando Valley,Ca.
How can i block these numbers on my Iphone 5 so they cant call me anymore?
MacBook Pro (15-inch Late 2011), OS X Mountain Lion (10.8.2)