I am traveling to the UK with a transit flight that stops in Doha (Qatar capital) and I need to buy a SIM card in the transit zone of the airport.
The Doha Airport's official webpage contains a link to a page of maps of the various terminals and concourses.
The maps for Transit Concourses A, B, D, and E show various facilities (seating, restrooms, customs/immigration desks, etc.) but do not show any shops or stores in these areas.
There is no map for a Transit Concourse C, which may or may not exist. I've never been this airport.