Caller id says DAVITA. No message was left

Calls but doesn't leave a message when i don't answer.

Did not leave message when not answered.

Davita is a group of kidney dialysis centers.  They let their patients use phones since cell use is prohibited during dialysis. I've had problems with patients abusing their privileges before.

I don't usually pick up  when I don't recognize a number. Did this time on a whim and caller (Davita) started to talk about reverse mortgages. I hung up.