Trouble with Minecraft: Story Mode?

I have episodes 2-5 downloaded to my IPhone 6 already, but when I go on the app they say "purchased but not downloaded" how do I fix this?

Rasaun 25.03.2016

Uninstall re-install? If this continues i'd honestly contact the company

Anonymous 26.03.2016

Maybe restore purchases

Zane 26.03.2016