You may also be able to check the repair status online here:
Apple Repair and Repair Status Check - Official Apple Support
Edit: You can also contact the Apple Store where you left your laptop for service to get a status update. I have seen a couple of recent posts on this forum where people were not able to get a status update from the Apple Store. If you encounter this problem, then speak with the manager since someone at the Apple Store should be able to make an inquiry on your behalf if the laptop was actually sent out to an Apple mail-in repair depot instead of being repaired at the store itself.