Your post is what is a bunch of hooey. You do NOT have to update your DNC registration - ever. Didn't you read the info on the site when you first registered your number?
https://www.donotcall.gov/register/reg.aspx
Legitimate telemarketers do pay attention to it. If not on the DNC list, you'd be getting even more calls.
Called my mobile today...man with a heavy Russian accent asked me if I was interested in lowering my interest rate. He asked me is your ___ credit card balance $____ ? Definitely phishing for info.
Not sure if a call from a foreign country helps with the do not call list. Not does a company calling that folds under one name and reappears under another. Sorry. The DNC lists are a great theory. They kind of fail in actual practice