Booster

Hi MarioG, sorry for the delay in responding.  Were you playing the game with a mobile device? 

Please note that the boosters are saved to your device and not the game data, so you can use them when offline too. This does mean that any updates, crashes or device changes can cause these items to be lost.  For this reason, we do not recommend storing too many of the won boosters as these can indeed be lost unlike Gold Bars.  You can read more about it here:

https://care.king.com/en/alphabetty-saga/superstar-information-post-where-did-my-free-boosters-go-on-my-mobile-device

Hi Mario, since you have played on a mobile device the boosters can be lost.  They suggest that you use the boosters while you play the game instead of accumulating them.