If above process doesn't get your answer. You can create the support ticket at this location: https://paytm.com/care/ticket
It takes 1-4 days for this process, so do take follow up with them via phone or the customer service email. You can use the email for customer service here:
In case if you have any issues with the Web based ticket then you can call at following: 0120-3062244. I am sure they can reply to you request. And do give them necessary information about the order to initiate the refund process. It helps if you co-operate with them at this process. Do explain them the situation and the product related information so that they can get more idea on the process.
Hope this issue gets resolved and you get your money back from the seller.
It has been observed that they are prompt to answer such requests. If needed, you can escalate the issue to the concerned authorities.
If it not resolved, I would advice you to take the matter to social media. Taking it to twitter would be more helpful in getting the resolution.
Live....and Let Live!