I have been getting these calls for months. I have reported the number to donotcall.gov on a routine basis. Like you, I called back and pressed 1 - the calls have come on an almost weekly basis since then. They now come from various different numbers too. Area Code 480 seems to be the newest area code.
These creeps called my husband's cell phone---that he uses for business---and started out with that lowering credit card debt crap but when he asked "who" they were the male caller told my husband ugly, ugly, ugly things like "F...you and your wife and your kids and your dog" He was nasty.
We, too, have been on the do not call (DNC) list since its inception but these sleezy ones pay no attention to other people's rights.