Overall I can see that there are quite a few people who have a dead pixel here and there (usually in the middle of the display somewhere) but just another guy who has similar yet even worse lines than you do...
https://www.mobileread.com/forums/sho...9&postcount=10
I'd still recommend you to exchange for a new one, even if that means waiting till monday... Don't let them talk you into repairing .. I don't even want to know how long it'll be gone flying to kobo ...