Almost double the charges (please investigate custom)

I bought a item last year and this item had a 6 year warranty on but the item failed,so I claim it for the seller so the seller send me nuwe item. As I went to customs they said I did not payed Tax on this item but this item did past through customs and went to my home the original item that was damaged. Custom want to charge me now 29 dollars rand value plus 35 % for import tax and tax that is more than the value of the item that is robbing the people *****ing. Someone please need to investigate customs things can't be like this we already pay so much tax in this country now they will rob you on a item that had a warranty on.