Government is not the justice system. It is one of the basis of Democracy: separation of power. You can absolutely take your government to court (at least in democratic country).

Class action doesn't exist in all country though. Each person that want to sue the government might have to do it in his own name.

Why not fine the company, Medicall, responsible for taking the calls? Or Voice Integrate Nordic, who supplied the callcenter-system, depending on who is at fault.

A class action is not likely. Most Swedes will probably see this as a minor setback and just move on.