I filled in all the details and got an email in reply. Next day I got a call from Sandisk, who asked me a couple of questions regarding the nature of the issue. Also I verified the SD serial number. Post that I got a RMA number in my email.
Next I had to go to Rashi Peripherals in my city (they are the authorised service center for memory devices in India for various companies). Once I reached there, I handed over the RMA number and got a brand new 64-GB micro-SD card. Saved almost INR 1500.
Since my card was corrupted, I was concerned about the data, so they allowed me to break the SD card to my heart’s content and handed them over the pieces. Great service by Rashi and Sandisk.
Edit: some users are downvoting every comment of mine, after asking for help or suggestion. Since I wrote the **bleep** **bleep**ing post, I get downvotes for trying to help?