Flipkart — Delay in delivering products

Not delivering the products on time and mentioning that customer has asked to deliver after two or three days without consent. These guys are cheating in collaboration with flipkart by delivering too late and not taking responsibility.
We cannot reach them as well since flipkart doesn't give their number and protect them. Each day the delivery date changes and whenever they want to deliver they will. Even if its a week after their assured delivery date we cannot do anything. All they say is there is some logistics issue and we will never know when it will be delivered since the date changes everyday.