New swiper here, dump didnt work when swiping, no error message

[Sml9]

I purchased a 201 dump, copied both tracks onto a blank magstripe card with msr, went to walmart and grabbed an item under 100 just because it was my first time. Went to self checkout and when it was time to pay I swiped the card, said try again insert or swipe, when I tried again it gave message " insert or swipe" I tried 5 more times before leaving. No error message or card declined or anything. I live in Canada where almost all cards are chip and pin, altough almost everywhere accepts swipe. any advice greatly apreciated.