Skybag — Wheel badly damage

I purchase a skybag from Mumbai, I only used it once while I was coming to Kolkata during coming out from station it's wheel badly damage even I was pulling very carefully. Now I am not able to carry it. I purchased it on 9th of April from INCS Mumbai. it is under warranty for 3 years. I want it to repair or replace it. When we go to purchase sales man will say it has a good warranty service but when something happens then no one will look into this. I am really very upset by this type of service. Like this they are just cheating to the customer.