Coca cola disappointment

I bought 3 750ml 6 packs of coke at a store in Lenasia. A day later my partner, daughter and I opened a can each and coke was flat. It tasted as if there was water mixed in the coke. I then called Coca Cola (call centre) and was advised that a consultant would call me shortly. A week later on a Thursday I received a call from a lady ( could get the name) stating that she would come the next day as she was late. I agreed and awaited. A month has gone by and still no response from Coca Cola. I bought 10 (ten) 2 litres on Friday...that is my dedication to Coca Cola. Thank you for nothing.