Xiaomi India — Mobile speaker not working

Address:

Jaipur, Rajasthan

I have purchase Xiomi MI 4i last month from Flipkart via Invoice no. BLR_WFLD[protected] dated 20.07.2015 (invoice attached). Suddenly my phone speaker has stopped working due to which now audio is not working in songs, ring-tone, videos etc. Although, sound is coming through earphones.
I am unable to find any complaint mail id on official website of xiomi. Also, helpline no on the website viz. [protected] is not responding i.e call not transferring to their persons. I have tried lot of time. hope I can find some solution here. I expect them to replace my phone since this is an unacceptable problem for a new phone.
My Contact details are:
Lokesh Kumar Jat,
[protected],
Mail id: Lokesh.[protected]@gmail.com