If a purchase was accidentally made on your Android device by a friend of yours or by family member using your account, it is possible to request a refund at:

https://support.google.com/googleplay/workflow/9813244

❗ If you find a Google Play purchase made with your credit card or other payment method which you didn't authorize, besides, it wasn't made by anyone you know, please, report unauthorized charges within 120 days of the transaction at: 

https://support.google.com/googleplay/answer/2851610?sjid=7478795453529829610-EU