It is CBCS, a collection agency. The number that shows on my caller id is: 603-755-6303 which appears to be a local number from the Farmington, NH central office. However, Customer's can by a bank of VoIP local telephone from a LEC (local exchange carrier),  CLEC (competitive local exchange carrier) and other types of phone companies. The numbers appear to be local, as is the case for me. Farmington is about a 45 minute drive from my home in Kingston, NH. They have call centers in Ohio, Florida, Michigan, and NY. Their website, https://www.cbcsnational.com/industries-served.php, says, "At CBCS, we serve the healthcare, utility, government, and financial services industries.". We owe a hospital a ton of money for a surgery my husband had in 2014. I believe that's the debt they're calling us about. Since they never leave a voice mail, I never call them back.