It is nuts
@Tiki, and I think you might be right about a UAE SIM card, and I have been told (by a phone salesman in the UAE as well as my son) that it is because the govt wants to force people to use the govt owned telco. Until recently, there were no taxes at all in the UAE, although they did introduce a GST style tax about 2 years back. However, my son says there are all kinds of “taxes” on things sort of like the ”lazy tax” where businesses like banks, insurance and phone companies gouge existing customers because they know it’s too hard to change provider. And this seems to be one of those situations. Along with the outrageous cost of phone calls from Australia to UAE - and my providers (Telstra for actual bill and Optus when I learnt to call and ask about rates BEFORE making the call) have both confirmed that it is UAE costs that make it so expensive after I questioned the amounts charged for my calls. talk about phone bill shock - I nearly died when I got the bill.
you can use messenger and what’s app to text, but not for voice or video calls. Every now and then, they have some sort of amnesty, usually when a competitor telco tries to open up, and then you can use these services for a while before they block them again. It’s just so frustrating. So maybe you were there in an amnesty, or maybe it was your Australian SIM.