Bought a bottle from a shop. Got a dead fly in it. Where to complain?

in this given situation it is fault of service provider he duty bound to provide you product up to market standard therefore you can go for replacement and for compensation in local consumer redressal forum against the manufacturer company for their fault. beside you can file complaint to the approval authority for selling contaminated and substandard material in the market.

Your legal remedy will trigger if you consumed the soda and suffered some bodily harm/disease. Just by virtue of identifying the fly, you will be entitled to the cost of the whiskey bottle and marginal compensation (maybe INR 1000 or so), if at all the case is filed before the consumer forum and an order is passed. As long as you are safe, my suggestion would be to read to the manufacturer and let them know.