What about codeshares the other way round? I have Spanair tickets for a round trip between FRA and PMI on LH metal in July, bought through expedia.com. They have a Spanair ticket number and Spanair flight number but are operated on LH metal.
HTB.
Same situation here. ZRH-BCN-ZRH, LX metal, JK flight number, JK ticket, Expedia issued.
Just got off the phone with LX. They are not touching the ticket and told me to call expedia. Apparently LX will not honor the ticket and they asked me to ask for a refund through expedia. Not looking good at all...
Update: managed to talk to expedia. According to their internal information, JK is not issuing any refunds at all therefore the ticket is lost and they cannot help. They told me they tried to get in touch with JK but it's impossible. They suggest I contact the credit card issuer and/or my travel insurance and see if I can get some protection there.