Selling products that don't work

So today I when and I purchased a clear blue pregnancy test at clicks in kenilworth centre which I paid R95 for.

I used the product and it gave me error message that is no where on the box or information.

I contacted Clear Blue and they said because the are based in the UK the will not be able to assist me with a refund but I need to go back to the store where I purchased the item.

I contacted Clicks customer care who said that I need to go back to the store and ask for and exchange or refund

So I go to the clicks store in Kenilworth centre stood there for 15minutes waiting to be assisted and then one of their manager approaches me and ask how he can help. He did not even get to explain myself as yet and he just said No they cannot assist and I need to go to a GP to find out.

My question now is. Why are you selling default products if you cannot assist with refunds as this was the result of using the product incorrectly but due to a fault on the product

Stacey