Selling Nightmares to the buyer

Amazon india linked up with 3rd graded 3rd parties and even the a to z warranty is a night mare for the coustomer. I have a lil faith for buying online products and this kind of service tends us to think twice before buying online. My products seal was broken and a part was missing. I can agree that can happen once in a while. But atleast they should try to repay it without any hustle. I have not opted for cod. I paid through my debit card. I believe here wat I have done the mistake