Xiaomi India — purchase phone in feb month ,now its not working

I purchase phone in month of February now suddenly display stopped working.
I took it to service center, they are charging rs 3500 stating physical damage and liquid damage.

phone was purchased three months before, hardly used (as i have one more phone of lenovo which i am using without any issue from 4 years) it got liquid and physical damage without being used..
there was small crack on up end side, but amazon guy told that is not an issue, but now because of that i am forced to pay money.

i am very upset with mi as i used hardly and now i am paying without any reason and you guys will deny it stating its my mistake but trust me..i am not going buy any mi phone further nor let my friends or family to buy mi phones.

thank-you so much for such a beautiful experience