It's the Red Cross folks reminding you that you can give blood every 56 days.  They really need O+ if you have it.  (Other types too)

This number calls my cell 2x a day and never, ever leaves a message. I never pick up for a number I don't recognize - why waste the minutes? Looks like Red Cross, eh? If they were serious, they'd leave a message. I used to donate regularly, but because of this constant harassment, I've quit.

@Phil same here. They used to call from an 800 # for me. then they sneakily switched #s on me. I really don't like the pestering thus I've stopped going.

They call me c. 2-3 times a day.  # is not identified and they NEVER leave a message.  Last time they called (c. 3 months ago) I asked them to stop calling.  I told them about a very bad experience I had with them at a work bloodmobile event and now give religiously every 56 days ELSEWHERE!  I wish they would stop calling!!!!!

Why wouldn't the Red Cross leave a message tho?  They call every 2-3 days and call 2 or 3 times a day.  EXTREMELY ANNOYING.  I just want them to delete my number, I haven't donated blood in 5 years.  Annoying phone calls will not convince me to donate again.