Problem buying additions – Kids Sounds - Moo Box Quiz Review

My son loves this app but he really wants the transportation and animal additions to it that you can purchase separately. But when you try to purchase them an error pops up and says they are not available. He is so upset that he can see them as an option but can't play with them that I may have to delete this app. Very frustrating.
Review by Narf1 on Kids Sounds - Moo Box Quiz.