ONLY WORKS FOR GOOGLE PLAY STORE

Step 1) Buy the in-app purchase you want from the app itself.

Step 2) Go play.google.com and click the gear icon on the top right corner and select " My account"

Step 3) Find the purchase you made under the order history and click the 3 dots on the right and click report a problem

Step 4) Select this option " I purchased this but did not receive it"
And write this: When I tried to buy it, the app force closed and the stuff I want is not received "

Step 5 ) They will refund you immediately if the purchase is less than $10 and if it is more than $50, it will take a few days.

Note: Only do this if you are really unhappy with your purchase.