Sour Yogurt

We bought a pack of 6 Danone jogurt and only after a couple of days found that all were sour and watery and it wasnt past expiry date and we hqve a new fridge. After sending a couple of complaint emails i never got a response, even phoned in and was only told to send the complaint on email. After this experience we'll rather stick to other jogurt brands but Danone I'll never buy again very disappointed.