He called me again today and I answered - it was clearly a joke call. Later I looked it up online, and turns out someone I know must have used the JokesPhone app to send it. I downloaded the app myself to test it out, and there they have the exact same call I got, prerecorded.
They include pauses and everything to make it sound like you're talking to a real person. They then record your responses and send it to the person who ordered the prank call.
I MAY have brought this upon myself by signing up someone I know for a spam email service... One such service is MailBait, in case you are interested. :U
Well, best stop here so as not to start a full-on prank war.
Glad it wasn't the cops. <_<