In case you have made a real-money purchase in the shop you have the full right to refund that purchase. The terms and conditions are defined by the store you made that purchase in (App Store, Google Play Store).
To trigger a refund, you should do the following. Open the store (App Store, Google Play Store) and request a refund for the purchase. The platform manager (Apple, Google) will make sure you get your money back. The platform manager will also determine, if new purchases can be made after that refund. This is not within control of Super Spell Heroes.
Once we are informed about a refund, the game will remove the granted reward from your account. Make sure you have not yet spent those rewards. In case you have already spent the rewards, your account might end up with a negative balance. While your account has a negative balance, most game features are not available until the negative balance is resolved.
In case you have any issue with this process, please contact the support. Our team will help you.