Postnet Walmer 6th Ave, Shocking Service!!!

I asked Posnet Walmer 6th Ave. To collect parcel for me in Cape Town, next day delivery.. it was for chronic medication.. heard nothing Tue morning so I called to find out.. the kept me on hold , then eventually, told me she would call back.. eventually after about 45 mins was told that courier was at collection point, but there was nothing for me.. told ME to contact hospital, to see what problem was. Turns out, after many phone cslls to hospital, that the courier said he didn't have a name.. but they had all my details.. Anyway, long story short, its now Thurs . Ive missed couple of days of medication, and It finally arrived, and they still want me to R185, for overnight delivery.. What kind of customer service is that?? So what exactly does overnight delivery actually mean.. whats the point.. Dont go waate your time or money there.. shocking service!!!