This is a known issue and the development team are currently working on improvements for the next update.
The issue is currently that we do not have a progress bar on the update screen - this is coming in a future update, but currently it is difficult to tell how far into downloading the new Levels you are.
Can you please try the following to resolve this issue:
1) Restarting Booty Quest with a different internet connection (e.g. Wi-Fi instead of a mobile 3G/4G connection
2) Leave your device updating Booty Quest for a longer period of time. If you leave the downloading screen for a longer period (e.g. around 20 minutes) on a stable connection (preferably Wi-Fi) this should allow the update to install. You may need to keep an eye on the device to ensure it does not go into sleep mode.
If the issue persists after following the above steps, please raise a Support request and we will be able to help further.