Gojko88,

I had a very close experience like you, it took me more than 2 months to get it solved. You heard nothing from them, you call them, they promise to call you back, but you wait without any response.
I bought also a Rimowa bag sometime ago, and after just a few usage, the outer shell cracked (like yours). I sent it back in and was later told that since they do not make that anymore, they just sent me refunded me the money, leaving me searching for a replacement bag. [makes me also wonder about the quality of these Rimowa's after hearing all they hype about them]

Sometimes, I am so surprise by how German efficiency works in reality.

Cheers!