Earned reward got locked again in Bowling

Re-posting for Naresh via Facebook post:

The Bowling App rewards are a bit buggy. My son and I won all of the rewards, the last one being the Ghost faced ball (the one with the blue flames). However after opening the App after a week, we saw that one showing up as locked again. My son is very upset that hours of playing the game has been wasted. Any idea if the team could help here?