Unable to Change Country of Billing Address in Apple Store

I am a Belgian but living in the UAE. As AZERTY keyboards are not available in the UAE, I tried to order a new macbook pro in the Belgian online Apple store, and let it be delivered to my parents' house in Belgium. My only issue is that I can't change the BILLING (or invoice) address to any other country than Belgium (delivery address is ofcourse Belgium as apple does not deliver in other countries).

I called apple Belgium for 30 minutes and they did not know why the dropdown menu for billing countries only contained Belgium. They recommended me to order the laptop as a guest (not with my apple ID, which is connected to UAE as a country), but even with a guest log-in, only Belgium as billing country appeared in the dropdown (see pic below).

I mailed the VAT refund department (as my billing address needs to be outside Europe if I want the VAT to be returned), but they referred me back to the same phone nr I called before... I also called the apple shop in Brussels and they also did not know.

Any solution for a situation where delivery and billing address are different countries?