User invite email not arriving - user stuck in pending

Hi, I'm trying to get actual help because the only support apparently available to me is the chatbot, and this community.

We have Basic Zoom licences but we are paying for Zoom Webinar and Zoom Phones. I've invited a new user to be able to use Zoom Phone, but the invite email never arrives. I've pressed the resend email multiple times, and the user is stuck in Pending. I've deleted the invite, re-added the user and the invite never arrives. So now we are paying for a Zoom Phone licence for a user who can't even get into Zoom.

I've seen similar threads where the solution is to contact support. I'm not sure why support needs to get involved -Does resend invite not actually re-send?

How do we submit a ticket or contact support?