Xiaomi India — Too long time for changing battery which is on warranty card

Address:

400056

Dear sir /madam
i had given my Redmi note 3 which i had purchase last month but there was battery issues with phone it was given on 28/09/2016 . they said the problem will be resolved within 15 days and the phone will be given back on 15/10/2016
but on 15th they said becoz supply is not coming it will be given back to you on next thusday but now one month is completed n still we had not got our phone back from service centar .
if only battery replacement is taking one month then i don't how your product is going to survive in market . i hope you can understand my situation from last one month .
thank you