That's right, if in any way the Job finish abnormally or the communication with the vCenter was aborted, the snapshots are still there....
Are you using VM layer Snapshots or Disk Array snapshots?
From Console or Webconsole you can try the following:
In Menu Storage > Array Management, click on the Array and the click on "List Snaps"
If Snaps are still mounted, use unmount snaps or force unmount snaps (based on Job ID)
After that use remove snapshot or force remove snapshot.
When finish, run Reconcile Snaps
If that doesn't work, first remove snaps in vCenter or array system and then run Reconcile Snaos again