sold me a rancid product

I purchased hemp seed oil from dischem it is the lifestyle brand, I go there once a month. I could not find it so I ask the assistant store manager to show me where it was he took me to the shelf and gave it to me. I purchased and only opened when I arrived back in gauteng, it had a very rancid smell and when I read the label it said keep rrefrigerated which is a surprise to me as the Hemp seed oil was not in a fridge at dischem klerksdorp it was on the shelf. And if logic serves me right if the manufacturer say keep it refrigerator ed it is suppose to be in the fridge at dischem, but at klerksdorp dischem it was on the shelf. I would like my product to be replaced it was not cheap and I expect better service from dischem this is not acceptable.