I have had quite a lot of fun with a few Indian “BT” Call centres when they call me because my internet has been compromised. Run them a merry dance acting like a complete tech dimwit (once for almost an hour) before finally telling them I know it is a scam and asking them how they can live with themselves? The responses are usually denial, followed by a lot of swearing and then them hanging up! I figure if I’m wasting their time they’re not scamming someone more vulnerable.