No cell phone; no "messages" Verizon's response

In an area (where my office is), usually the Verizon wireless network is satisfactory - not great but satisfactory. The wi-fi is strong within the office building.

Today, early this morning, none of the iPhones (including mine which is a current OS on a 12 Max Pro) nor my iPad (also Verizon) show any "bars" of Verizon service.

I'm unable to make nor receive calls. I'm unable to send "messages."

A so-called "chat" with Verizon (using a MacBook Pro and the internet) netted this result. I was "told" that because it's Labor Day, there "must be more people using the system" and that accounts for the poor service. I've never had this issue on previous holidays. And, this is, in fact, a sparsely populated area.

Does anyone have suggestions to restore cell phone and "message" service. I've reset every device and done all the routines that Apple calls for.