Harassing & Rude Callers

I have registered my home, work, and cell phone numbers on the national "Do Not Call" List.  I have still been getting calls from "Credit Card Services" at my place of employment.  The call starts with a recorded voice, Erica, stating she has inportant information about my credit card and how to lower interest rates.  The prompts say to press 1 to learn how to lower rates.  I press 1 and have repeatedly asked them to stop calling.  Today, I received a call from them (my 3rd one in 2 months) and was connected to "Jessica" who asked if I had pressed 1 to lower my interest rates, to which I replied, "No, I pressed 1 because I am on the Do Not Call List".  She yelled, "I don't care if you are on the Do Not Call List, you pressed 1 to lower your interest rates!"  She then hung up on me.  I called the number (228) 209-9560 that came up on my caller ID and it had been disconnected.  Please help!