Covering up ceiling damage
Should be simple enough to fill it with joint compound yourself; I doubt you need a plasterer. Fill and strike off level with the ceiling. Wait for it to dry completely (24 hours is a good estimated time in most houses), fill again (the stuff shrinks) - after 2-3 coats, let it dry completely and sand lightly (will be dusty), then paint.

To evaluate drying, look for dark spots where it's thicker (not dry yet) and feel the surface to see if it's cooler than the surrounding wall (not dry yet.) For homeowner patching it's rarely worth getting the "setting" type joint compound which actually sets (more quickly) rather than drying - in larger projects or for a pro it can speed the process along. For a homeowner it will mostly be wasted (small amount used from a large bag but the large bag does not remain usable after a long time in storage) and adds complication (it's a dry mix rather than premix, and the mix instructions/quantities are often for mixing an entire bag at once.) 

Using a small tub of premix (drying type) and taking a few days will generally be more sensible for DIY.