請代譯英文，急

The colleague who used to follow up with this invoice has already resigned. To my best knowledge, there is no PO number available on the invoice that was mailed to you. Besides, the payment has been overdue for a long time.


PO number 是否 = Purchase Order number?

Our co-worker who used to handle this invoice was no longer with our company, as I know the invoice attached with the sample which was deliveried to you has no purchase order number, and this invoice was already paid long time ago.

Followed up this single colleague already to leave very for a long
time, I knew was serve as send distinguish for yours receipt, should
be has po no. Front, moreover this list you already very much were
owing pay money.

跟進這一張單的同事已經離開很久，我所知是用作寄辨給你們的發票，應該是没有po no.，而且這一張單你們已經在很欠前付款了。
My associate who handled this transaction had left this company for quite a long time, I've found that this was an invoice for samples and it has no P/O No.
Besides, the amount of this invoice is already paid some time ago. Thank you.
(or, Besides, this invoice is already settled.)