I assume you are from India (using Flipkart).
You can try the Service Centre and see if they do spare parts and you might be able to get them for free/small price.
Looking around, there are some places that do them, but not to India. Like AliExpress.
If you're not bothered, you can always put tape over it until you need to use it again to prevent dust going in. Not exactly ideal, but it does keep the dust out.