The same thing is happening to me. . Said they were from United parcel service and needed to deliver court documents. I told them my address is public knowledge, go ahead and put them in the mail. They've called before. Very irritating!
I let them no i know for a fact I owe no money and real government offices already have my contact info. Also, let them know I'd pass their number on to local police station as they like to know who latest scammers are. I heard lots of traffic in the background like they were outside talking on a cell phone.
I have been getting calls from this number with the caller ID showing Jason Witten as well. No one ever answers. I have had it call as earlier as 5:15am to 9:30pm.