pathetic Managers service and Expired products disgusting

i had bought a sparletta iron brew from roots butchery in pinecrest mall and the cool drink was expired , i noticed that the item had a bad after taste after drinking from it thats how i ended up checking the expiry date i then contacted the store and spoke to the store manager of which he was rude and abrupt stating that he can not assist for a bottle of cool drink that has been consumed as though we go around checking expiry dates futhur more for a manager to behavior in such a manner is pathetic