Please Help! He is going to pull out vinca soon.

Vinca can come back from the roots when pulled. Don't be surprised if you see it again.

The leaves won't bother the Vinca at all, quite the opposite, and make excellent mulch.

Place netting on top of your vinca (use landscaping pins to hold it in place for a few weeks) prior to the leaves falling, and then pull it up to collect the leaves when most have come down.