Calls me everyday, not sure who it is - sometimes someone is there sometimes not

No idea who this is.  They didn't leave a message so their number is blocked from here on out.

This number calls me everyday, but whenever I answer, no one replies, and when i call back, there's a recording that says their office is closed. I don't know who this is or what they're doing, but it's getting pretty ridiculous.

Calling won't answer