Paytm — To return.. And refund my money back...

I recently bought a sony power bank from paytm... Thats the worst product ever seen.. Its not even getting on... Worst electronic device... Waste of 1000rs... Even i contacted customer service... There was no response.. I mailed to [protected]@paytm.com... For atleat 10 mails... No reply at all.. I shared photos too recording it... Dont knkw why seevice was started... Please any one help me in this mater to return the product and refund my money back...