Croma - Not getting refund within 7 days of defective product

I bought Lenovo slim * laptop from croma sinhagad store. Within a month it had to change motherboard but even then the laptop could not run. Then after further rounds, they gave me a replacement for the product. But the game starts now, the product bought on * nov didn't even start on * th i.e. it again had same sleep and shutting down issue. Then went to them on **th, they were very reluctant to solve the problem even didn't notice. But after demonstrating the problem, which even croma technician himself identified as very genuine for replacement ( have his video as proof plus those of issues faced by me), they directed that to service centre and then after * days( which is a very long period in pune)I get a call that your laptop has no problem. Now according to croma rules actually I would have got refund on the spot at **th. I highly doubt them, they are telling to collect laptop and just go. I bought laptop on educational loan, ***** is a big amount for me please help.