Xiaomi India — Defective power bank

Address:

Bangalore, Karnataka

I bought mi 10400 mah power bank, but it stoped working after 3 months so i went to service center they said you will get a new one, but its been more than 2 months they are not providing my power bank, i called to customer care they said we are raising issue and will get back to you but still i dint get any solution.the service center people are not very friendly they are not supporting for this . this service center is in kormangala 6th block .please help me with my issue.