**************** - SARS Custom duties /South African Post Office

I bought something online from Instagram and when it eventually arrived at Capemail Hub I went to collect and was expecting to pay some kind of customs duty on such a small package but not to be charged half the value of the item!, which is determined by your proof of purchase). The post office says to speak to SARS and vice versa. Who the hell do I speak to regarding this?

I honestly feel like I committed a crime by buying online and now I am being fined/penalised for it!!!!!!!