They don't abide by the do not call list because they are criminals. The only people the list stops from calling you are legitimate companies. Charities and political groups aren't bound by the list, and criminals ignore it.
Bingo!!! Criminals don't care about the law and they sure in heck don't care about their they call. Hence, why the number continues to change and why they hang up.
They don't care! You can block and buy expensive phones, but they will still call.
If enough people would just ignore the calls, and stop giving personal information over the phone, then the problem would be resolved.
This scam continues because people keep falling for it. The criminals want you to act on impulse to get your credit card information. That's it. Just theft! And folks fall for it daily, and that's why we all continue to get the calls.
Know the signs. Out of area, fake number, always a recording, always lower interest rate. You should know it is a scam.