HR is unavailable to speak now due to the meeting

Context: The HR is unavailable to speak now due to the meeting.

1. The receptionist requested to call at 12:00 P.M due to HR was in a meeting.
2. The receptionist asked me to call at 12:00 P.M because the HR was in a meeting.

Are these sentences correct?

The receptionist asked me to call HR again at 12.00 pm as they were at a meeting.

Use either "the HR department", "the HR team" or "the people who work in HR". Don't use "HR" to refer to just one person (unless it's the unlikely situation in which just one person is responsible for all HR work in the company). However, you can use "HR" on its own (no article).

The receptionist told me that everyone from HR was in a meeting and asked me to call back at noon.