Samsung Online Store voucher: The worst **** in online shopping ever!!

In August I bought a 65 inch Samsung TV from Samsung online store. I chose to buy from Samsung online store because they were running a promo whereby you get R2000 voucher to use on their online store. Weeks later I received my voucher , and I tried to use it to buy a sound bar. To my surprise, when I entered the voucher, it said I cannot use the voucher on that item. I called in to ask if is there any list of items that we can use the voucher on, and guess what, they said they do not have such list, I just have to try item by item on their store. In other words , browse through thousands of items from fridges to cellphones to washing machines until I get the item that accepts my voucher. They told me that's how it is and there's nothing they can do about it!! What a **** ! The only reason I bought my TV on their online store was because of this voucher, and I'm starting to think the voucher is not usable at all, it was a trick to get us to buy from their store.