I would seriously reconsider that course of action; it could be construed as GBH of the earhole. They have your details on record. I think the best course of action is to put the phone to one side and play some weird noises to them. Have an audio player of some kind to hand with a ready made recording on it.
Find number who calls you
If you have an annoying question in your head 'Who calls me?' - you came to the right place. This is a user supplied database of phone numbers of telemarketers, non-profit organizations, charities, SCAM artists, and other companies that don't leave messages, disconnect once you answer, and simply interrupt your day.
Getting unwanted calls from strangers? Just type number you don't recognize and get more information about it! Maybe you are not the only one who gets calls from that number.
Keep this page updated, guys! ;-)