I think the main issue here is that EK were difficult to contact on the phone to make a new booking, and it taking 3 hours to reissue.

I sympathise with the valid complaint that EK now has removed ticketing staff from outstations, even from their busiest ones (BKK, LHR). Especially at BKK where there are staff all night - I don't think it's beyond EK to have one staff member who can do ticketing, even if that means do it at a workstation at the check-in desk.

However, for future reference, best to call DXB directly.

I don't really have much sympathy for the no show fee or the fare difference to buy a new ticket, as no show means, you haven't turned up by flight close - which would have been 1930. When I miss the flight, that's on me and I take the risk if I've bought a cheap ticket (or really, I never buy non-flexible for this reason as I have been caught out too many times before). BKK's weather and traffic is notorious and I put that really entirely down to the pax.

In terms of SIM card - I recommend getting an eSIM app like Airalo for situations like this.