Computer Mania - Missold

On 15 July 2023 i purchased a new Asus M515DA R7 from computer mania at Somerset West Mall. I specifically told the sales guy what i require which was a laptop with a battery life of 4hrs which will accommodate for loadshedding because i study and am about to write exams. He confirmed that i would get 4hrs battery life out of the product. On the first day of use it showed 4hrs but then it diminished and now i only get 2hrs out of it if i am lucky. I then took it in on 22 August 2024 to have it checked out and the technician stated that i can only get 2hrs30 battery life out of it. I am extremely upset as i was missold, if he told me that it does not have 4hrs battery life i would have purchased another one. Now i am sitting with something that i do not want as it does not meet my requirements