Excellent service, but expensive delivery

I bought an item from Zasttra through Bidorbuy and made a mistake with my order. Zasttra were SO helpful. They gave me a gift voucher for the wrong order. The delivery fee charged by Bidorbuy was R99. The delivery fee charged by Zasttra was R258! I had to order directly from them in order to use the gift voucher. I received the product in record time. I shall really buy from them again in future, but ONLY if they change this exorbitant delivery fee!