Myntra - Incomplete delivery made and no one is taking responsibility

I was placing a Tee order on myntra wherein i need to buy something else of approx *** Rs. more for free shipping. I placed order for Mamaearth shampoo and an offer got reflected on myntra that if i purchase mamaearth product of *** Rs. more, than I will get free conditioner. I placed the order and received a confirmation message for mamaearth * products. Before delivery as well, there was confirmation message of * products but as soon as i received my order, there were only * products for which i paid the price, the free conditioner was not there. I immediately generated complaint and called customer care. It was strange that the customer executive told me that there was no offer going on, i told him i got the confirmation on message and i can share screenshot as well but he discoonected without listening. Again, next day i called and explained my query, call disconnected and received message that my query has been resolved. I kept on calling them and writing to them but without listening, issue resolved. * days later, i received a message that the team has checked the product details, and the conditioner was delivered. It was quite strange that for initial * days, they were either disconnected or saying that there was no offer prevailing and than a sudden confirmation. I requested to connect with Senior or lead, but no response. Even neither they arrange call, nor they raise complaint, no transferring of calls to sr person and everytime a simple answer we have raised complaint, u will receive a call back within ** hours. Since July **, **** i am waiting for the call for which i daily place request but no actions has been taken.
Is this the correct behaviour of dealing with customers? If I saw some offer on website, I received confirmation message but no product than whom should I reach to. moreover, no one is ready to take responsibility.
Nd its not about a free conditioner of *** Rs., I can also buy that because i do shopping for more than *k on myntra, why would i chase them for a product of *** Rs. But its about fraud and the mistake for which no one is taking responsibility.