When you see a number from out of state, especially one that you don't recognize, either don't answer it - that's what answering machines are for - or just pick up and hang up. Simple. IF you want to give the courtesy of 5 seconds after you say hello and they don't answer, hang up. I just did.
BEST thing to do is accept the fact that there are these sorts of things out there. At least they are not hurting you. Unlike a situation like mine, where someone has stolen 7 pages off my website, "beefed it up" with lots of pixs and then goes to dating webs where he stalks lonely women, falls madly in love with them and then asks for money to bail a friend out of jail in Nigeria or China. The sad part is, lonely women do fall for this and have been taken for many thousand of dollars. The purpose of the website is to show that he is a successful entrepreneur.
Another scam is taking info off Facebook pages where everyone tells everything about themselves, friends, neighbors and relatives and it's easy to get the address phone numbers etc to make the contact. They will call you and say a young relative is in jail, needs bail money and "Oh, grandma, please don't tell mom and dad! It's only $4500 and I now you have it." Good reason not to get involve with FB where everyone tells everything.
Best advice is beware and if it sounds too good to be true, that's probably what it is.