Angry [Q] Yezz A4.5 1GB RAM

Hy , im new here , i'm bought an yezz andy a4.5 phone , and i wanna root this phone but i can't , i used every "one click root"but it doesn't work :SRSroot , kingoroot , framaroot , can someone help me with this?and another question , how can i find 4.4.2 original files , i wanna upgrade my yezz to 4.4.2 android , i can do this?is an quad core processor (1.2 ghz) and 1 gb ram , sry for my bad english !