S7 edge display overheating and lagging problem

a month ago i noticed a pink and green lines on my screen i did all the trouble shooting that I've search in the net and nothing works but worst after a week the screen just die it flickers then blank screen u can see all the buttons notif lights are working so the screen is the only problem. wen on the store where i bought it disappointed as they told me to pay for 1200dirhams its like 300dollars way no. even my warranty expires for just morethan a month im hoping for samsung to help. anyway since the time i bought the phone it is overwhelmingly overheating and lagging most of the time i have no chance to return the phone bec right after i bought it i went to travel for a month. hayy very sad and disappointed