If you have the time, lead them on and keep getting escalated as if you want to buy. You can eat up 20 minutes of their time and THEN tell them to get lost. That costs them money and they might back off calling you. If you waste their time at least there is some justice. Courts and the feds don't care.
I will contact the FCC if necessary. This (302) 394-9971 from Wilmington, DE, is nonsense and completely unprofessional. They asked for Robert, nope, and the hung up abruptly before I could even finish saying, "Stop calling here." They've called four times today. Nonsense. I'm already on a Do Not Call List for this kind of ridiculousness.
Other users report that this is a car warranty company. I have not talked to them, but these morons are fairly persistent. I have had 4 calls show up in my call log today despite the fact that I have them configured to receive an “out of service” recording!