I think this happened coz u took ur car for servicing, the service people decided to cover ur air filter with a plastic bag before washing your engine,
which is all good,
however, after washing, they shut the bonnet, washed the rest of the car, started the engine and took the car out for drying,
then they realised,
oh twaadiiiii!!!
forgot to remove the bag before starting the engine, so there was too much pressure and this deformed your air filter,
atleast this is the sequence of events which I am assuming happened,
its not the air filter's fault.... this would happen to any high quality air filter too if u covered it up with a plastic bag and started the engine, revved it and drove even a few hundred yards.
Lesson: Next time stand there when they cover ur air filter with a bag and keep standing till they finish the wash,
tell them atleast 50 times bhai thelaa utaaray baghair engine start kiyaa to yeh tumhaari zindagi ka aakhri dinn ho gaa,
and make sure u kep the key in ur pocket so no one can start the engine without your knowledge.