Look into setting up Google Voice. Its a free service and it lets you take complete control of your phone by playing a message to callers numbers you choose stating that your phone is no longer in service. It sounds just like your phone company's disconnected recording.

Received call at 3;57 AM .........WTF

Same as the other reports - no one there.  I've been getting quite a few of these lately from different numbers.  Some have been at 3 to 4 AM!  I suspect they are harvesting 'active' numbers for selling to telemarketing companies.

Same as Irene above.

Answered the call but no one was on the line.  I put the call on hold, went back and checked, still nothing.  I hung up and called the number back and a message said "The number you have dialed is not in service."