I'm going to try the same thing, wait til they are about half finished and then start playing Boots Randolph's "Yakity Sax. " Do it every time an Indian scammer calls me. Pretend interest then hit 'em with saxophone music. Give 'em the Benny Hill treatment.
WARNING: Aggressive Scammers!
Received two call from 347-269-2686 and 347-983-5097 stating they were from the investigative bureau of the IRS and there is an warrant out for me because of delinquent taxes. I played along, asking them when they sent out the letters, how they got my unlisted phone number, etc. They provided non-answers, but had my correct address. They were very aggressive and threatened to send the police to the house to arrest me. I told them I knew it was a scam, and they hung up quickly.