Disappointing progress

I am disappointed with C*****'s slow reaction to deal with complaints. I logged a complaint on their website twice on the 21September and received a response on the 25th requesting detailed information on the spoilt product, followed by a promising call from their consultants,the query then evaporated. I then received a call from another consultant, followed by an email request for similar details as requested on the 25th. I resent the information and have since not received any feedback. On average it's now almost a week without a way forward but vague calls and progressive actions. I was even forced to purchase a different milk brand due to the disappointment from C*****'s delayed urgency. I have approximately eight unused cartons from the same purchase,due to the the fear of finding similar green mould-growth,forcing me to log the complaint. I need answers!