Lenova - Poor gaming laptop performance

Bought gaming laptop in Nov ****. This started giving battery issues starting Jan ****. It has to be on charger continously while in use. Remove the charger and it starts showing less battery signal within **-** mins. This is gaming laptop yet only * games are installed and it is giving poor performance on even just *. Complaining since Jan up until now. It is getting worse to the point that while toggling between programs using alt+tab it moves so slow that it shows complete black screen for few seconds. Opening up google or youtube takes somewhere around *-* seconds. Slowness is not giving problems with performance only, even playing a game is issue there is so much lacking there and my strokes and what is seen don't match. every month I am calling these guys to no avail. I have been requesting to send someone to have this checked but all they do is check system on remote desktop and suggest nothing is wrong with the system. It is so clear that do not want to admit it is a faulty system as the calls are recorded. They are clearly passing on time for the warranty of this to expire. Pathetic system with more pathetic after sales services.