I've been also getting calls from this number at all hours of the day and night, plus the number 972-797-6412 and also an unknown call that does the same screeching static in my ear! Its ridiculous, I've called the number but have never got a recording just once and it said the number was disconnected but then that same night i received a call from that same disconnected number!
Just called customer service to complain and was told it will take UP to 30 days for it to stop! Wow, apparently they're not doing the up to 72 hours anymore and saying it's up to 30 days now!
I received a call today from this number, 972-372-1723, and didn't answer. I looked up the posts and was glad, at the time, I didn't answer. I later found it truely was an emergency. On-Star was trying to locate me for an emergency concerning my mother who was in her On-Star equipped vehicle. Luckily everything turned out good, except she is upset with me for not answering.