Bought a 4W cabin travel bag on Myntra, the trolle...

Bought a 4W cabin travel bag on Myntra, the trolley has broken 3 times already. The service center rep says that I broke the bag by using at the airport. Also he told to not use it at airport.
I did not buy this bag to keep at home. I would appreciate if someone reaches me, I would like a replacement or a refund.