Ah it's on warranty. That changes things. You should just get it replaced by Philips.

I can't see the part so I can't help you much, but usually this axis goes through the holes from the outside and there's a groove that has a matching ring in the earcup that keeps it from falling out. Then there's a retaining clip on this groove that locks it in place. It may be hard to take it off.

Things like that can be made with DIY methods, and tools are welcome. You know, measuring calipers, a saw, sanding paper and about an hour of free time. You can't just repair it, you need to reconstruct the entire part. You do that with metal tubes or rods and whatever you can think of that you glue together to make that shape. If done right, it's more durable then the original part. OF course people who can model in 3D use printers for that.