It's a 諺 (ことわざ). There was a song released only a few weeks ago with that exact name, which was translated as "Ups and Downs":
https://www.youtube.com/watch?v=hCfwA8U87QM
But it doesn't sound like what you saw in that place was a poster of a Hello Project girl group? ^^
I think the literal meaning of that proverb is something like:
"fall down 7 times, get up 8 times"
七 (なな) 転び (ころび) 八 (や) 起き (おき)
August 11, 2015 at 8:37pm