I have done exactly this! Given them fake credit number and other info, and kept them online for about 10 minutes. When I finally revealed what I'd done, I suggested they quit calling or I'd keep wasting their time if they did. I did this about 2 months ago. I've only gotten 2 calls since then. Before that I was getting 4-5 a week.
Received 2 calls from this number today both with the same recorded message with a woman's voice saying if you want to lower your interest rate, blah blah blah............has to be a scam because credit card companies don't do that sort of thing and can't believe anyone would fall for this bs anyway. Thankfully I don't have to answer such nuisance calls and my answering machine takes care of it. I'll bet they are not even located in Oregon at all just using a phoney number on the caller id. Get this same type of call from other numbers too and it's always the same woman's voice with the same exact speech. Something needs to be done to stop these scam artists from calling people on the do not call list, once and for all.
I received two message in my answering machine, and the caller iD says "Lower Interest". Then when I called back, the recording said thanks for calling back. Press "1" to remove your phone number from their list. Hope it works.