junk email about saving money on credit card rates

Junk call purportedly from "Credit Card Services" -- claim that they are hired by Visa, MasterCard and Discover to contact "their cardholders".  Visa and MC are "associations" and not card issuers (banks issue Visa & MC); you can't be contacted on behalf of the association.

Bottom line: telemarketing and I have no idea how to stop or report this clear telemarketing abuse

Telemarketing call. Pressed 9 for an agent. She told me I could lower my credit card interest rate and was calling about a Visa balance. I do not have any credit cards. When I informed her she was violating the law by contacting me as my # is in the national do not call registry, she couldn't get off the phone fast enough.

Report the number to the do not call registry That has always worked for me in the past

I have lots of fun keeping a whistle by the phone (after receiving these unwanted calls for years, despite being on the do-not-call list). When Card Services calls, I hit 9 to talk to an operator, and when someone comes on the line I give 3-4 short whistle blasts, then politely ask them to stop calling me. One idiot actually got irate with me, which provided some good comic relief to the whole episode.

One thing I've considered, but haven't implemented, is answering female operators with the most explicitly obscene suggestions I can think of. And I haven't ruled it out yet.  This is war.