worst store

<p> we purchased a 2LT milk and it was bad the same day we opened the milk , The expiry date was set for 29/11/16. We sent someone the very next day to return the milk and the store refused to return the milk. Firstly this is bad practice and goes against the CPA. The store said they dont sell bad milk . how can they determine that the milk is good or bad . Please sort this out or I shall take this to the NCC.</p>