How to make an appointment with GNIB for card following approved visa?

After 6 months of waiting my critical skills visa was finally approved. I received the letter via email and arrived to Dublin airport with it.

I have checked every day, all day, for 3 weeks now on the Burgh Quay registration website to make an appointment to get my ID card. There are never any appointments available, for any day, even 3 months in the future. I have called the numbers listed and sent emails. No one responds.

I have to leave the country briefly in a few weeks and am concerned about re-entering without a valid GNIB card, but there seems to be no way to receive a card since it's not possible to make an appointment!

What am I missing? How can I solve this?

They usually release new slots at 10 am, however this last week I tried and it wasn't released any slot.