Milk got spoilt while still sealed and its not kept in direct sunlight or im any high temperature for it to go off

I purchased 6 pack milk i use 3 and by the time I got to the other 3 it got spoilt the seal box bloated and puff up... I contacted them and they told me someone will call me back and assist me and no one has... this is poor customer service and I am a good customer I always buy first choice long life... I am very disappointed about the poor customer service and the ability to help me. Its been 1 week now and no feedback.