Amazon India — seller not giving refund for faulty product

Address:

401107

Dear sir, madam, please refer order number:
[protected] invoice no scja-311 order date 25.12.2017 delivery date 29.12.2017. Product description : mr. Shot instant running water heater, auto reset | b0148dwk2k (Sv-01-rar) hsn:8516
Sold to me by yes we associates have been interacting with mr. Shridharan of this co. Mob no.[protected].
After speaking with rep of above co faulty water heater sent back once to above mentioned co address. Thereafter product replaced but same found again faulty and giving cold water and with the request of co's rep mr. Shridharan, video of the same sent to him.
I have conveyed him that i have lost my faith in product and asked for full refund including 1999 + courier charges 84 (Sent earlier once) = total 2167/-
But co rep says they will not refund 2167 /- i have asked amazon customer support but hey refused to deal with me and asked to deal directly with seller.

Please intervene and give me justice ask seller pay back full refund with courier charges spent both the times.