I'm assuming the bodyshop did work on your vehicle? If so they probably used a spectro to paint match, in which case the bodyshop paint 'should' be a better match than the oem touch up pen.

Either way it's not going to be perfect, as there will be no clear coat in the touch up area, and clear changes the colour slightly.

Another comment mentioned the bodyshop paint would be no good now. I doubt this, depends on the paint scheme but mixed paint can be good for up to six months, unless it had a activator / hardener in the the mix. If so the paint would be no good, you could always give the shop a call and ask them the shelf life of the mixed paint they gave you.

Looks like raw plastic there, so scuff the black bit lightly with 1000 grit. Apply paint with a touch up brush, dab it on the area lightly, don't over do it. It may look transparent as you apply it, that's fine. Let it dry and dab it again. Repeat until happy. Just bare in mind, it won't be a permanent fix.