KitKat cash and carry blames customers for their wrong pricing

I was so disappointed with the service I got at Silverton branch I bought dish towels. At the checkout, Price was not the same as the one I saw on the shelf. I went with the cashier to confirm what was displayed. Billy (Billium). Told me point blank that I have to pay the correct price. Reason being they have over a million goods in store its not their fault. I was recording because he was rude. He threatened me told me to delete. He went on to say "I took a price somewhere else and placed it there. I was spoken to like am a mad person. kit kat group is not ready to serve the community rudest management ever. I still have the videos of the whole scenerio as well as the pictures.