These are Indian telemarketing companies, usually calling on behalf of insurance companies. If you tell them to not call, they make a point to call you again and again. Do not call block does not work.
Can't really understand why people call back numbers that they are not familiar with. If its important they will leave a message. If they don't, why waste your time?
They call several times every week it goes to voicemail and they listen for a couple seconds and hang up. posters below said his choice home warranty telemarketing. zillow or a realtor probably sold my number.