JIMC parcels

Good Day I ordered an item from the UK via Royal Mail, it was said to have arrived in SA on 19/03/2018. I tracked the item and it has been in customs since there, particularly the JIMC A. I’ve been calling customer service and fAiling to get a response been to the Rustenburg and Pretoria post office and been told it will arrive after being cleared at JIMC. I desperately need this package by the 12/04/2017and I was wondering is it possible for me to go to JIMC and collect it myself.