Mi India — Non working power bank given to mi in warranty period is not received back even after 1 year

Address:	382415
Website:	www.mi.com/in

I bought Mi 10400 mAh Power Bank on 15-10-14. WHich I submitted to MI authorised service center in Ahmedabad on 7-3-15 as it was not working properly. It has been a year since then . I have called numbers of times.I mailed them. But there is no response. EVen service centers are takling in ruse manner and have insulted me so bad.I request you.