Bad custom service

I went to Pnp Quagga center today looking for an air freshener. I saw a price tag for a twin pack on their shelves Written R19.00. When i got to the tills they refused to give it to me.I was told that the bar code of the tag and the items are not the same so they wont give it to me. One stuff member gave me attitude as i was explaining my story. She too one of the air freshner and threw it in my basket and she left me hanging. I have taken pictures of what i have seen on their shelves concerning their prices.