Originally Posted by NWIFlyer

Yes, there is - under Star Alliance rules the operating airline must respond within two weeks of receiving the claim. If they fail to do so then A3 can force the credit through and charge LX for it. You may well need to press A3 to do this - the airlines don’t generally like to do it.

The problem comes if LX does respond, but either just acknowledges the request or denies the claim. At that point it can drag out forever ...