Mate just take it bk and say the battery is ****ed or it keeps crashing and they will replace it. Then on your new one get a screen protector if you think u,need it.
this is terrible advice. Let's lie about a defect and get a new phone because I scratched my screen. This is a scumbag move and is equivalent to stealing.
Screen scratches (coating and glass) are usually caused by small pieces of sand or grit, in pockets or on surfaces. You can take keys and other instruments go the screen without damaging it but the tiniest spec of sand will damage it. It sucks that it happened so soon to you, unlucky.