Unacceptable Customer Service

I have a parcel that is currently being with withheld by Postnet South Africa Chatsworths branch the owner is very rude and have no business ethics whatsoever, she blocked me on WhatsApp and decided to even block the owner of the shop where I purchased the item from, I live in Lamontville which is very far from Chatsworths and I requested for this parcel to be moved to Berea where it’s more convenient for me the owner of the shop decided to block me I have since complained and escalated the matter to Postnet SA and have not received feedback or acknowledgment on the matter