URGENT: Need Help due to payment and transaction issue

So I decided to buy monochrome in ZZZ(a game) and bought the highest value monochrome bundle but here's the problem google pay shows that transaction has been successfully completed but google play says there was error during transaction process and no monochrome has been added to my account. Now neither I have the money as it is spent(as google pay tells the transaction was successfull) nor do I have monochrome which I have paid for(google play tells me there was an error during transaction). what should I do serious answers only.