Hero Electric — Hero optima battery not well

Address:

18/18,brhastipura gali no. 1,arya nagar

I am Vipin Kumar from Rohtak (124001), Haryana.
I purchased a hero optima lead battery model 10 months before and now the battery condition is worst day by day.
Give average of 10-12 km per charge.
Rohtak dealer is KL automobiles & I contacted him many time & now he is not responding well.Now he says he will not change the battery under guarantee.And Hero electric company no. Is getting out of order.Where I will get my issue resolved.Please let me out of this.