DTDC Courier & Cargo — Courier not received to Client

I dispatched a crucial document to the client via DTDC on the 6th of July, 2023. The tracking number for this shipment is U24650211. However, as per the client's feedback, they have not yet received the document. Surprisingly, the tracking status indicates that the document has been delivered. It has now been over a month since the dispatch. I have reached out through email and made many phone calls to customer care in an attempt to resolve this matter, but unfortunately, I have not received a satisfactory response. The content of this letter holds significant importance.