Lenovo ideapad - Money Refund Issue

We bought a lenovo ideapad **W***D*IN laptop from reliance digital on **th of june . It's having a **wh battery . As per reliance the battery backup should last upto * hours but it drains within * hr * mins . We demanded for replacement but our demand was constantly denied and they kept ignoring our issues. At **% of battery the laptop keeps hanging and misbehaving though it have *gb ram . Also when we went to the service center , they just said its ok without checking. At reliance digital ,assistant Kumar called us to show the proof and we went and used the laptop and showed the quick drainage of battery but then also they are harrassing us. They even called another customer infront of us to take the same laptop's review but the customer said that his laptop gives a really good backup and he's really satisfied. So, it proves that we got a defective one and want our money back as soon as possible as we have lost our reliability both on the product as well as the company. We Even mailed to the lenovo head Mr. Panda within * days of purchase but they also said that the battery is ok without practically checking it . Please resolve our issue as soon as possible. Below my contact details are provided.
Phone-**********, **********
Email- deepaktwinkle@gmail.com
Adress- Ga-*** , sailashree, chandrasekharpur.