Dell G3 3590, not being able to detect the graphics card again even after sending it to Dell for fixing

Hello everyone,

I need someone's help as my Dell G3 is acting up again. Previously it had the problem of not being able to detect the graphics card back in April-May. I sent it to Dell for repair in June and so far it did work up until 19th of August. The same problem popped back up with my laptop being unable to detect my Graphics Card. The fans would also periodically run fast for a few seconds and stop again. After 5 minutes it starts to rev up the fan and stay silent again. I am really frustrated as this is the second time this is happening to me and as a student I am in need of a functional laptop. I want to know if I need to send it to Dell HQ for repairs again. 

Which bring me to my second inquiry. Would it be possible to exchange my laptop for brand new one as I feel that this one is causing me too much problems. 

If there is anyone who can help please reply as soon as possible please.