Scam calls getting out of hand

Previously it was mostly spam calls that I'd get on a regular basis. Now I'm getting scam calls, the DTDC scam, the TRAI scam, electricity bill scam etc etc. They call using numbers from the Middle East, Phillipines and even the US. I usually waste their time and laugh at them. However they can be very intimidating for someone who isn't aware that it's a scam. We all know that the authorities can't do shit about this, so what is a realistic solution to this? Edit: if you get such calls when you're free, bait them and waste their time. Nothing infuriates them more than that.