worst service delivery

Purchased goods from canal walk pnp. When opening yoghurt, noticed a chemical smell, tried the yoghurt and tasted the same. Phoned the call centre and the came to collect the product after I gave the batch number. I received a standard response today and a voucher. I explained to the agent when I called that I will no longer be purchasing parmalat products, why send me a voucher??? What was the outcome on the tests on the yoghurt? When I phoned the call centre today no one answered and the service at head office was appalling. Wish I had taken the yoghurt back to the store. At least I would of gotten my money back.