I booked a premium economy ticket on SAS from LAX to DUB with one leg from LAX to EWR operated UA on 787-10 with premium plus seats. The fare class is A for all legs. However, when I put in the confirmation number into United website, that leg shows up as normal economy booked in class S. Calling both parties hasn't been helpful. UA agent said it's not their ticket and there's nothing they can do to fix it. SAS agent said it's premium economy on their side but United is known to accommodate codeshare passengers in regular economy. Is there anything I should try to do? The flight is tomorrow. Would the airport agent be able to help?