make sure your name is on the do not call registry. document when they call, and ask them to remove your name from their database.
they will call you again, because the company banks on the fact that people are too lazy to go through the hassle of filing a complaint. file a complaint.
https://complaints.donotcall.gov/com...k.aspx?panel=2
rinse and repeat.
edit**
although it also sounds like they're trying to scam you as opposed to just soliciting business... go here for that:
https://www.ftccomplaintassistant.gov/