So i'm not a great rider yet, 1 day 7 hours worth of play time, but i finally managed to beat inferno iv in roughly 28 mins with 400 odd faults, i was so pleased i managed to beat it but then to my dismay... no achievement

do i have to do this again or is there a way to get this to pop?

*edit* i have just completed all tracks on welcome to the abyss, this achievement didn't pop either. I tried hard resetting console then played a track for a better medal with no luck