Acer - Newly bought Laptop not working properly

I had bought a new acer laptop from Flipkart in the month of July. The laptop worked fine in the initial months but from the month of November, I'm facing following issue in my laptop.
*. Laptop got stuck while working and have to restart the laptop again due to this.
*. Whenever we put laptop in the sleep mode, it automatically gets hanged and gets shut down, due to which I have to restart my work again.

When I connected with acer support they send a technical person, and he told me that this problem is occuring due to moisture problem, there is a black layer is there over the SSD and the Motherboard. I'm using other and other applicances also since long but never faced this issue ever and this problem happened in this newly bought acer laptop which is just * months old. Though I purchased the product from Flipkart my warranty also got expired in the month of October which I have to restart by mailing the invoice of the laptop.

I have asked them for replacement but they are saying, we don't replace the product after * month of usage. They are just changing SSD in future I can clearly see the black layer on my motherboard so I have to be ready for this issue again.

I have asked them to replace this defective product, either give me the new laptop or refund my money, but they are saying no to this.

Can you suggest me that, can I file case against Acer for providing me the defective laptop and saying no when I'm asking for replacement or refund