I hope you guys find this helpful. Like may of you I have been registered with the do not call list. What this people are doing is trying to lure you to confirm your information (Name, address, number, etc.) so they can sell it to telemarketers. They use what is called a proxy switch that uses a number not currently in service to try and place untraceable call to your number. Banks also use these type of "services" to try and locate debtors. What they are doing is not legal and if found out they can get in a lot of trouble. My best advice is not to answer and then use *59 to trace the phone call right after they call. (it traces the source of the last call received) once you have put a trace on it three times you can submit it to the police.
I work at night and always get these calls early in the morning when I'm trying to sleep. It's a female saying "good day" in Spanish. It reminds me of when we were kids and made prank calls. I will block this call.