Hello I bought WAYFINDER'S GUIDE TO EBERRON through dndbeyond app . Google play charged me and then I got error message about problem with finalizing purchase.

I got mail conforming from Google that I got charged but since its digital goods I cant get my money back . 
No I have no money and no book.

What can I do to fix it ?

You need to contact google first to confirm what happened with your transaction. If it failed to complete, they need to issue you a refund. If it the transaction completed successfully, they need to provide you with a transaction ID that you can then show to DDB customer support to honour.

Hello! 

Please reach out to our Support team, and include your transaction number/ID from Google, which will help the team verify your order. They should be able to assist you further from there.

Thank you very much for reaching out! 

I've been trying to purchase books on the app with Google Play and it has work most of the time but the past few days it's been giving me nothing but errors and it is not on the Google Play side because I rented a movie on it as a test so it seems like it's on the DND Beyond end please help