The fact is that it does happen.

Cases being dropped off the conveyor to the cargo hold, rough treatment by baggage handlers, etc. I concur with the comment above, but in reverse.

1. Notify the air carrier you were ticketed on when you noticed the damage. That company handled your case, assuming we are speaking of checked bags, and are the responsible party to first deal with. Document your claim with photos and keep it factual, and civil for best results.

2. The early model polycarbonate Rimowa cases were first heralded in the mid-1990's and I was one of the first purchasers in Germany. Ours, a Blue XXL lasted exactly two flights: Leaving Germany and arriving back enroute to Neuchatel. Lufthansa Frankfurt compensated us for the full amount, without question, as it was an LH model and I carried the receipt.

It is not clear if your damaged case remains under the 5 year warranty or not, as you mention an early model polycarbonate case. The corner cracking on the rounded radius is happening to the Salsa models, but you do have a solution here too.

The Rimowa repair shops can install corner metal protective "caps " which would cover the crack. If that works for you, I would contact Rimowa and speak with them about what options they can provide you.