You can fix your phone by flashing a correct ROM. Chinese phones can't get bricked. If you flash wrong preloader, you won't be able to boot it, but just get a correct preloader and flash it by pressing and holding VOL+ button before you connect the phone. It will start working again. Check for original ROM at www.NeedRom.com
Also using MTK Droid Tools will tell you real chipset. It can't trick you by telling you it's a quad-core if it's dual-core.
You can also blame the seller and ask for money back.