I paid for lufthansa/they sold me a seat on united!
 

On 7/25/12 I purchased a round trip ticket from Lufthansa Airlines for Flight #7616/7617 Newark to Rome for $1542.90. I called Lufthansa at 800-645-3880 to get the seat assignments and was informed that I had to call United Airlines instead. Lufthansa had sold me a seat at a premium price on United - flights 962/963!!!!! I absolutely did not intend to fly on United or I would have bought the ticket from them directly for $1325.89 ($217.01 less than I paid Lufthansa). I specifically chose Lufthansa based on their reputation for on time flights and in flight comfort. I specifically wanted to avoid United for those same reasons.
WHAT A RIP OFF. I want to know how this is legal for Lufthansa to advertise flights that DON'T EXIST and sell tickets to unsuspecting consumers on a completely different airline at a premium price? I would NEVER have flown United if I had been aware of the true relationship between Lufthansa and United. This is wrong.
I want a refund of $217.01 from Lufthansa since now I am stuck with the airline tickets on United, an airline that I never would have flown in the first place.

It's quit commen for airlines to share and sell seats on companies in the same alliance. Usually it will be show operated by in the flight details.

If this is the case I don't think you have a case

Welcome to the marketing scam known as "codeshare" where airlines put their identifier on other airlines flights and sell you the ticket. It is, unfortunately, not illegal. U.S. law does require,however, that the "operating carrier" must be disclosed when choosing and purchasing tickets. The wording is generally "Lufthansa flight XXX operated by United Airlines". You might have a case against Lufthansa for the higher fare only if that statement was not displayed anywhere (on the internet, on your invoice, or your itinerary confirmation) or the Lufthansa agent failed to mention it if you purchased your ticket through a telephone reservation agent.