Incessant calls

I am in the Denver area, and I keep getting calls from 303-883-**** - the last 4 numbers vary, from a Christy who says she is from Credit Card Systems and I qualify for a better rate.  I know this is a scam.  But they keep calling using different numbers, which I continue to block.  When I ask her what state Credit Card Systems is out of, she completely ignores me and says "Now, can I ask you some questions?"  I know I don't need to pick up these calls but I want them to STOP.