Who called from 3055872004

Same thing...no message.  I've seen this same "company" listed under the same phone number, only the last digit is 5.  They are trying to get your personal information.

Got a call from them, didn't know them, didn't answer, and they didn't leave a message.

I, too, got called from the number 305-587-2004 and it appeared as "GCS." They hung up as soon as I denied being the person whom they called for . . .

This number called me, but when I answer, they hang up.  Why do companies do this?

Those people are associated with US Bank.  They are attempting to pip supplemental or
additional health care insurance for you and your family.  (If you have any business dealings with
US Bank, those 'affiliates' are exempt from the DONOT Call Registry and can call you during
normal business hours.)  I told them where they can go with their insurance - we will see
if that don't put an end to the calls...