SWISS cancelled my return flight and left me stranded

I booked a return flight with Swiss Air. For Premium Economy. However Swiss air has left me stranded in Europe after cancelling my return flight back home. They keep telling me I never took the flight. I submitted images off a stamped passport and my bag tags for my luggage, as well as photos of me in Europe and they still telling me my flight was cancelled due to “no show”

They are now refusing to acknowledge that I took the flight and refusing to provide a solution.

When I call the service centre they tell me the flight is confirmed but then a few hours later I receive a cancelled flight email.

Swiss air is not helpful and I will never fly with them again