Typically, any issues experienced whilst opening your Box Bonanza is a graphical error, such as the amount won not being displayed correctly or the Box not opening after clicking on it. This can be caused by a dip in the stability of your internet connection or a caching error. Whilst these can happen on occasion, you can find out how to alleviate these issues here.
Please rest assured, any amounts credited from your Box Bonanza game will be added immediately to your account balance. You can also double-check the amount credited via your Reward History in the My Account > History section.