Whether or not your online letters of recommendation have been submitted displays in your Activity page:
A recommendation that has been submitted will be marked “Completed!” and this status updates in real time. Even if your recommender has finished filling out the form, unless you see a status of "Completed!" the recommendation has not yet been successfully submitted to the school. You'll need to have your recommender log back in and try submitting once more.
If they need any assistance with this, they can reach us at email@example.com and we'll be happy to help.