Who I have the same questioned this topic

I've had Verizon for years because it had great signal in Scottsdale, zip code 85257, but for the last month the service at my work is so poor I can barely send and receive texts.  I am not the only person this is happening to so please don't tell me to reboot the phone, which I have done, nor tell me to remove the sim card, which I have done.  I want to know what changed approx. a month ago regarding the service.