This was gleaned from another comment: Supposedly a service to stop unwanted FAX machine calls. This really is a SCAM debt collection business.
What I did was submit my name and telephone number to FAXHALT to stop the middle-of-the-night FAX machine calls that woke me occasionally. Now I get 2 robo-call calls a month from a FAXHALT number that says "We have a court order to serve you for unpaid debts". Oh really, a debt from whom? Your cousin, the Nigerian prince, who has $2.6 million to send me if I provide my bank account information?
The calls are from 720-386-XXXX, the last four digits change regularly to confound your efforts to block the calls.