@Ciara

It is the countdown to Chinese New Year now. SAFEA Office's have been closed for a week now and will be closed for at least another 10 days.

If your school has not got the invitation letter in their hands they wont have it until the office reopens again and then you have to allow time for it to be sent to you.

Just be mindful of that and as Turnoi says do not book anything until you receive it. Even if you have been told it has been approved, until you have the invitation letter in your hands nothing is set in stone!