Xiaomi India — Xiaomy mi4i sound problem and working process is very slow

Address:	Buldhana, Maharashtra, 444303
Website:	www.xiaomy.com

Sir,
I had purchase my xiaomy mi4i mobile before 5-6 month before bt problem start before 2 day sound automaticaly very low that time i had not listening soung like audio and video song...
Sir i had contact to xiaomy customer care center bt they r not received cl
Sir second problem is mobile work process is very slow...
Sir in my city xiaomy service center not available...
So please sir solve my problem as early as possible...