Xiaomi India — Mi band 2 refund have not received after returning faulty bandh on 3rd january 2017

Address:	Thane, Maharashtra, 400608
Website:	Mi.com

Dear sir/madam,
I have not received my refund for mi band 2 after submitting it on 3rd january 2017. I have called helpline no many time but they told me to wait for 48-72 hours. Its been 50 days after returning faulty band but no refund has been granted. Kindly solve my issue as early as possible. What are the options i can use to get my refund as early as possible