They have been calling my business fax line for a couple of years. I have blocked numerous phone numbers that they call from. Once they figure out the faxes aren't going through, they switch up the numbers.
I keep getting these calls too in the middle of the night. I called back the number and got on their do not call list. Great I thought. Not great....I got one this morning at 5:30 a.m. I don't remember the first number but this one was 720-386-2704. I will call my phone company and complain and try to get a block on all the numbers I have found in this thread, then I will complain to the BBB.
720-449-3655 aka 720-386-2758 called our business just a bit ago. Caller ID shows up as FAXHALT. No person on the line, just a fax machine. Not sure who they are, but they are calling our main business line with their fax machine.