EKO 55" Smart UHD LED TV

Got it today plugged it in and the screen had a funny colour in the top right hand corner , ridiculous, my children couldn't wait for it to arrive from Campbeltown big W 55" Eko waste if time !!

Picture only stays on for a few minutes than screen turns red blue white green

Was happy until two days ago.. bought a 55" from big W as a birthday present and it won't turn on!! Have had my tv for 2 weeks.. please help!

Tv worked perfectly for five weeks and now all of a sudden the colour has gone weird, all grey or blue. sometimes revert to normal after being off for a while but will lose colour. Now lost all colour to the screen except for closed captioning