Just had a chat with Trip.com, they apply for a flight change refund, but regarding the WUX flight they have asked me to get in touch with Juneyao myself. Lets wait for the flight change refund result.

UPDATE: Already received the confirmation that they will refund 9,93 EUR.

Another topic, I have booked the internatilnal NZ flights Melbourne-Christchurch-Wellington....online checkin in English etc. all good.

But I have also booked the domestic NZ flight WEL-AKL, and the whole check-in process, seat selection, paying for seats on the Air New Zealand website is in Chinese only, cannot be changed to English....