If the patent fee is overpaid, re-paid or wrongly paid, the parties concerned may request a refund within three years from the date of payment. Those that meet the requirements shall be returned by the Patent Office.
What you said belongs to the wrong model.
The procedure is:
The refund requester should be the payer of the money. If the applicant (or patentee) or patent agency requests a refund as a non-payer, it shall declare that it is entrusted by the payer to handle the refund procedures.
The refund request should be made in writing, with reasons and corresponding certificates? Like what? Copy of expense receipt issued by patent office, remittance voucher issued by post office or bank, etc. Should the certificate provided by the post office or bank be the original? Can't provide the original? A notarized copy confirmed by the official seal of the issuing department shall be provided. Should the refund application indicate the application number? Or the patent number? How much is the refund requested? Such as bill number, expense amount, etc. And payee information. Did the client ask for a refund through the post office? Payee information includes name, address and postal code? Did the client ask for a refund through the bank? Payee information includes name or title.