They hang up when I answer

I have received 4 calls since 7:00 PM until 8:00 PM, today 6-2-14 and was hung up on each time after I said "Hello" the 2nd time.

calls me everyday, leaves no message.

Call, no voicemail.

Caller claimed to be calling on behalf of Katy Rotary Club hosting a annual drive for helping disadvantaged kids by providing kids with movie tickets.  He asked me if I would like to sponsor any tickets.  I told him that I am not interested, and, then, he thanked for my time, then, hanged up.