Extremely Frustrated with level of service

I have a parcel that has been stuck at JHB International Mail centre since the 30th March 2019. I have spoken to various people at the Johannesburg & Durban Post Office Hubs but no one can tell me where my parcel is. I have been advised by the seller to contact SARS on either (+27 11) ********** / (+27 11) ********** . I have tried to phone SARS but no one is answering and the call gets cut off after a certain amount of time.

If it is at customs I am more than willing to pay for any duties but I am getting extremely frustrated that I can't even get a hold of anyone to be able to get any answers.