Cello — cello butterflow simply

Address:

Ernakulam, Kerala, 686671

I had bought cello butterflow simply 20n recently from paytm mall.in the beginning i just thought i was unlucky that the pens don't go very well with the ink after 1/3rd of its use.
This time i realise that this is not about the luck but it is a fact that the whole pens i bought for 199 rupees are in fact defected. The pack contain 20 pens and 20 refillers.

As a customer what remedy i have?

Ps: all the informations validating the claim will be uploaded at request