Good afternoon, Does anybody know if this 25w charger I bought for my Samsung is genuine? Was advertised as such but don't come in the original packaging...

My Samsung Galaxy A21s is only 8months old. Right from day 1, the screen seems to be unresponsive when the phone is lying flat . the top drawer cannot be dragged down , the corners are unresponsive.Its very frustrating . Where is the touch 'touch sen...