I sent items on the 10th of May 2024 using this courier company

I sent items on the 10th of May 2024 using this courier company. I run a apparel printing business, a customer paid for my service,I printed the required items and sent them from Postnet Westgate to Parktown to date which is the 7th of October my client hasn't received his items. I contacted them on the 12th of September because I wasn't aware that items didn't reach the person I intended to send them to. They said they will launch an investigation to date ai haven't received any feedback and now they are ignoring my emails