FallenStar You will need to provide your Google transaction ID (the receipt from Google) for Webnovel to verify. If you did not receive a receipt from Google, it means the transaction didn't succeed. If the transaction deducted money from you, but you did not receive a receipt, you should bring this up with Google support since they are the payment merchant, not Webnovel.
In addition, your problems might be a Google problem such as not having an adequate balance in your Google Play account, and/or your debit/credit card is somehow invalid. Again, this should be brought to Google.