Clone Problem

so i transplanted my rooted clones into party cups, hoping i can get the shoots to grow big enough to make 3 cuttings per plant. (main stalk, 2 shoots) ... but my shoots are not growing at all! they are tiny, and the plant is growing high...the heck?!
by now they are root bound.

transplant, and either top it or LST it to encourage shoot growth.

get bigger pots.....