Having been recently throught this bun fight with commercial and ops.
Can ATC please file MOR and send a ****ogram to company whenever you get even a hint of conflicting callsigns.
As pilots we do file internal reports when we see them. But then the darkside forces come into play. Some airports/handlers have to be forced into doing the season changes and will lie saying they can't do it. OPs get sent round in circles.
Commercial will come out with rubbish that it will screw with the booking systems.
Basically it can go round and round in circles.
If ATC file on it, it becomes an audit item which is brought up in the flight ops audit. Flights ops inspectors take an extremely dim view of open MOR's on this subject. Post holders get an ear full and the problem gets fixed.
So please file on it. More to the point and the reason why we as pilots file ASR's on it. When the inevitable screw up occurs you have a paper trail showing that the issue had been highlighted.