What I would have done:

1) If no Emirates counter staff; then:
2) Connect to airport WiFi and use their chat function.
3) if wait for chat is too long or not getting anywhere, use WiFi calling without SIM card to their 24 hour help line.
4) Ticket changes need to be refared through airlines fare department, so the customer service agent needs to contact internal ticketing desk.This is where you have to be insistent and based on the agents communication (they either know or don’t based on their response) and if not getting anywhere, thank them for their help and hang up. If you are spending more than 20 minutes, then something is wrong. Never assume any agent will call you back; even US airlines don’t call you back, even they ask for your number.
5) Fastest outcome is to use both chat and call and see who can reticket the fastest for you. So just need laptop and a phone.

Where you went wrong is being naive that you’ll get a complete DBX level of help at outside hubs and relying too much on the customer service staff. Repricing a ticket should not take more than 20 minutes and alot of times, you have to guide them through what you want and confirm if they can do it or not.