Order lost in transit but no one informed me...

On Friday I bought a gift for my father. I paid the R100 guarantee that my order will be delivered on Saturday. My order did not arrive. No one told me what is happening. When I track my order, it states that a replacement has been requested the order was lost in transit.

The courier had confirmed that he will be delivering my order what happened? When will I get my order? My father’s birthday is today. Kindly let me know if will still get my order today because I have paid extra to get it delivered o.

Also who can I call to speed up this process? I’m just so disappointed at the lack of service. No sms , no call, nothing. No one is telling me what happened to my order.