Dell India — I need format and they are doing reset

Address:

Mumbai City, Maharashtra, 400028

I was submit my laptop on 2nd october they are given my lappy on 3rd oct in 6.30. After that still its working slow when i ask them then thay are told me i am reset the laptop. I wanted my laptop working fast but still it was slow. Need to improve the performance. They are not supporting good and customer get truobled for that. Laptop still in warrenty period.