I had a claim in June for a damaged checked case ( also a Rimowa that had the retractable handle broken)
It took about 10 days for K2 to contact me. I also emailed Rimowa direct and still haven’t had a reply 8 weeks later.
After the initial contact from K2 things moved along swiftly. They now have the suitcase but have advised that the supply of parts to repair Rimowa can be slow at the moment.