Telephone fraudsters

The letters from Nigeria have long been replaced by emails. I've heard of people who were fooled and lost a lot of money, but fortunately I never responded. But once I was fooled by someone speaking in a foreign accent who said he'd met me in London a couple of years back and needed two thousand five hundred rupees urgently to pay at the airport (he was leaving Karachi and would meet me during his next visit which would be in two weeks). He then gave the phone to a native who spoke my mother tongue and who was his accomplice. I told the native to give the foreigner the money and collect it from my office later. The accomplice said he would send his peon to my office. The peon took the money from me, but apparently he'd been recently hired because he didn't know his employer's telephone number (nor did he himself have a cell phone). I never saw the foreigner or his accomplice again, but about a year later I got a call from the same foreigner with the same story. I should've kept my cool and should've asked the native to come to my office for tea, or I should've asked for his office telephone number or his cell number (he was calling from a public call office). But I lost my temper and told him exactly what I'd do to him if I ever met him. The native laughed and ended the call.
A couple of months back I got a call from a woman speaking fluent English, saying that she's a doctor in a local hospital and a patient had given my name and telephone number to her, because he didn't have enough money to pay for heart surgery. "He appears to be from your community, so I'm sending a man over for the cash," she said. I refused, because I suspected this was a scam, and this was confirmed a couple of days later when I met someone who'd been called by the woman, and he'd asked the woman for the hospital's address so he could go there himself and donate the money, but she'd hung up.