First, always confirm the recipient number with name before any transaction or start your payment with 1 rupee to check the right account. If by mistake you send the money to the wrong account, then follow these steps to get your money back:

1. Try to contact the recipient and request to send the money back.
2. Use the Request Money feature of Google Pay to get the money back.
3. Note all the details and history of the transaction and contact your bank or call your bank customer services.
4. If the bank does not provide you with any support then complaint a file with NPCI at https://www.npci.org.in and go to UPI Dispute Redressal Mechanism.
5. If you suspect fraud then file a complaint at https://cybercrime.gov.in/.