Losing Boosters Purchased

I keep losing boosters I have purchased  using both cash and gold bars. This may have been going on for a while, but most recently if I’m playing a game, and I haven’t even started a level yet, if the phone rings or I have to minimize the app, when I go back in the level resets and the boosters are gone, as if I used them. This has cost me a lot of money and it’s starting to look fishy. How can I get them back, or get a refund?