Honda Twister — Battery and mileage Problem

Address:

Bangalore, Karnataka

Myself Akshay B M,I bought Honda twister on September 2011 and recently it had battery problem. They told it will come under warranty. But now they are telling that there is no replacement and parts used for this are of not good quality and mileage is not upto the mark.They will tell that battery is Maintenance free.What i need to do