No service and no communication

I ordered an item from overseas and was send out on 5th May via Singpost, According to Singpost web site, delivery to South Africa is 5 to 7 days. It has now been 18 working days (23 calendar days) and the parcel not even in South Africa yet. I contacted Singpost, but keep giving me the run around. It seems they have no way of tracking their own parcels. I can not get an answer whether this parcel is lost, ****** or stuck somewhere??