When you download the new version of Lingopal 44, it may not have picked up that you had a store receipt.
Without deleting it, try just going to the store within Lingopal – the Plus icon in the top-right corner and see what happens – it should recognise that you are already paid up and show ticks on the items rather than prices.
Immediately after installing, only Essentials and Flirting categories are enabled.
Tap the Store button and login to the App Store when prompted.
The Store recognises you had already bought Lingopal 44 and all items are ticked, so just close it with the X button.
After returning from the store window, you will see the download indicator as it downloads new audio content.
All phrases are already enabled and you can go into categories and expand phrases. As they are downloaded, you will be able to play the audio.