Dumb move... They'll be back...
I didn't have voicemail from August through last Friday. (Our entire system went FUBAR and had to be replaced.) It was a pain in the ass... I couldn't cold call suppliers and give them my direct line because I might not be at my desk when they called back. The poor front office girl had to handle 10 times the usual phone traffic the last few months just so everyone wouldn't be glued to their desk.
Business by cell phone? Hell naw! Then I'll be getting calls at all hours. Obviously, some folks like sales and service people work better with cells. I'm engineering tooling. If something goes wrong we'll talk about it on Monday.