the worst service

I work at an optometrist and had to courier a pair of glasses to a client in Pretoria so I went to PostNet in Krugersdorp on the 3rd of January 2019 and requested for it to be couriered using overnight courier and door to door. The lady said they do not do Saturdays so my client will receive on Monday... Monday comes and according to the tracking services it was our for delivery but he did not receive it. Tuesday came the client calls me and say he will cancel his order. So I left it till Wednesday and Called today in the morning and the woman said she will call me back in 10 minutes but did not so i called again and they said she will call me back and I am still waiting for the call... the tracking services says it is out for delivery again