Dell - Battery and screen freezing

I bought a Dell Inspiron Laptop **** having express code number - *********** in the month of December ****. From the very first month, it shows the freezing problem means laptop need force restart for operating the laptop and battery is working for ** to ** mins. I complain about this problem many times to the dell company and they take online access to more than * hours many a time and they tell at last that the laptop is now working properly and the problem is now resolved. After this, the problem is not yet resolved and during this time I lost my work data because of the freezing problem because during freezing condition any key not work and we have force restart the laptop. I am a computer science bloc student sir and I need the laptop the most. They called me many times and take online access which in result loss of time for me. I got frustrated with this procedure because they unable to find any solution from the previous * half month but they didn't find any solution for this. Maximum times the laptop uses ***% disk without using any app in this and the end result of this is system perform too slow and hanging and sound problem. I called them many times but no solution. I told them either replace the laptop or provide me with any other laptop so that in parallel I can do my work while you taking online access of the same or tell me an exact time when the fault will be resolved. This laptop is manufactured faulty but they don't listen to me. In the last month, they said to me to deposit the laptop but I didn't. They again said to me the problem is now resolved but it is not. I have faced the same problem as earlier for sound, freezing and speed. Please help me. I already lost many data from my research work during its freezing. They stop responding to me now. My laptop also has a premium warranty in which they serve the customer by visiting their place but they don’t even visit my place to solve my problem. Me roaming here and there to resolve the problem. I got frustrated while using this laptop. This laptop is cost around ***** Rs which is too much for middle-class people. Please help me.