It remains a mystery that our phone carriers and the government continue to allow people to maintain phone service even though they use it to commit credit-card fraud and other felonies and scams.
Most of these calls are made from Voice Over IPs here in the United States, so when you try to do a White Pages or similar search for the carrier, it and its location will change on each search and provide inaccurate information. Using a free search like Stump The Monkey will provide you with accurate results.
As you’ve probably noticed, most of these phone numbers used in calls trying to get your credit card number have pages of complaints listed against them on Google as well as with their carriers. These carriers have the right to terminate them but they won’t out of neglect.
I recommend filing a complaint with the carrier and demand the service be disconnected. If the calls resume, report the carrier to the Better Business Bureau for allowing the conduct to continue.
I don’t understand why these carriers and the government are so nonchalant about this fraud, but if I was a bored attorney, I’d probably look into it. They could be liable for these personal losses if they were negligent in terminating those services.