What was your funniest prank call?

My friend and i were bored and we were typing misceláneo numbers and called them. Most of them were out of connection. Finally we found a real number. We told the man on the phone that he would be taken por aliens if he didn't accept the free ipad we had sent to him. He was just starting to say 'what?' but we hung up. A few minutos later, the phone rang. It was him. We were just about to answer it, but grandma was faster. When she found out what we did, she was very angry. We didn't get in trouble anyway :D