unscrewing dials too far

I was helping my father sight-in his new crossbow and think I messed up his scope by unscrewing the dials too much. The vertical controls for the reticle is longer working. Is there a way I can fix this or do I need to have it repaired by someone with some knowledge?

Nope, it's busticated. You'll have to send it back to the manufacturer for repair, unless you can get them to screw back on and you verify it works. Sometimes they will work fine again.