Laptops4u bad bad service and unprofessional

Battery centre Kroonstad bought a Dell i7 laptop from laptops4u cape town . We paid the laptop same day and extra for over night delivery . Then we waited 7 days for delivery just to see they only sent my laptop econo class that takes 7 days . When receiving the laptop when we switch it on you can only work between 15 to 20 min then it freezes and you need to power down and on again . i sent the laptop back next day 30 Aug 2021 nd they received the laptop on the 3 Sep 2021 but still nobody knows where my laptop is or when i will receive a replacement laptop after 3 weeks of payment