In case you enter a discount code during checkout that doesn't exist or isn't currently active, then you can see the message: “Unable to find a valid discount matching the code entered”.

Usually, Coupon Stacking is not allowed at Alala. However, the store will surely give out notice if available.

Yes, it has ever. It may not be available now, but it is completely possible for loyal customers of Alala to get it by tracking all of its promotion programs.

Yes. The old coupons from Alala will be kept on the page if it has not expired. New coupons will continuously be updated.