That's such BS and one reason I don't fly LH any more. LH and UA have revenue sharing on that route. LH got no less for your UA flight than they would have otherwise. Actually, you were originally booked on LH, probably paid a small fortune for your F ticket, and were inconvenienced, more reason than ever to admit you to the FCT.

Take this and relate it to the HON/SEN operational upgrade issue. LH favours the higher fare class one-off passenger of loyal flyers. Here are you, a high payer, getting shoddy treatment. So now LH is not just pi$$ing of a group of it's passengers, it's pi$$ing them all off.

May I suggest, next time LX if you really must stay *A, otherwise BA, where you pay and expect less from the start.