Please comment grammatically mistake

Subject: ABC Engineering Limited - Clarification of Purchase Order Number 12345678 with Quotation A123456 for HKD50,000.00 Retention Received

Dear Sir/Madam,

The BOC's Payee Advice dated 1 Jun 2022 referred.

Our record shows that the Invoice Number AB001 dated 22 Mar 2021 has already been used with another project and the payment had been settled on 11 May 2021.

Nevertheless, I will appreciate it if you could advise that this HKD50,000.00 is standing for the retention settlement of Purchase Order Number 12345678 with Quotation A123456 (see attached).

Thank you for your attention.

Best regards,