shoddy service

I bought something on bidorbuy and was assured by the seller that he would send it overnight from Durban to Cape Town on the 28th of May so that I would receive it the next day.<br> It is now the evening of Monday 1June and according to Dpe Couriers tracking, my parcel only left their premises at 17.45 today.<br> why did I pay for overnight?<br> Sloppy service!!!!!