EMS- failure to deliver on promise!

I spoke with a lady at the South African Post Office- Pinetown Durban branch about my parcel that needed to be couriered as a priority mail. She advised that if I used the EMS service, that my parcel will be delivered in 2 weeks. The parcel was handed over to SAPO on the 29th of March 2023. It is now the 28th of April 2023 and it still has not left SA. I paid R500.00 for this nonexistent service. Please advise on how I can take this further. The item being posted is a tissue sample and I am greatly concerned for its validity.