Thanks for the support.
I just checked the website, there are available slots on 25th on economy, I called Emirates but they said they can't change to that date because the website have some seats for NEW tickets only!
Can I ask for a refund and reserve new tickets? are all emirates tickets refundable? The lady on the phone said it will cost 25$ to refund for each ticket. But I'm not sure if my ticket is refundable or not. How can I check?

Bottom line, I need a way to travel on 25th and will tolerate paying 50$ for this. How can I achieve this asap before the remained seats go away?

Many thanks.