Hi hmattila,
Though I am not aware how EK handles involuntary downgrades, BUT am very surprised they downgraded a paid F to C.. i hv almost never heard of this..
And from ur experience till now, it seems EK has slipped big time in looking after its top paying clientele , I mean how are willing to buy paid F .. I would hv been really "$§"%"! pissed if this happenned to me..
Anyway, to answer ur queries, the normal ballpark rule is about 75% of the fare difference between F and C.. in LH, there seems to be a range of around Eur 1500-3000 or a combination of next flights in same class with Eur 600 - 800 compensation depending on the layover..But these are EU rules and guidelines , it differs from airlines ..As u waited for the next flight , I hope they gave u some IDB compensation atleast ??
My advice is you should also follow up with calls to their service center and be sure not to leave them ..You are entitled to compensation and a quite decent one at that..If you want some specific cases info, u may go to LH forum where they hv some details ( but nothing from F , all downgraded from C mostly )..
Keep us posted..
Cheers
Abhi