Retrieving collections after not syncing

Is there any way to retrieve flashcard collections that have not been synced to the ankiweb user database? The collection was made under the same ankiweb account that I previously synced one previous collection to, but I forgot to sync the 2nd collection and have subsequently lost 50 odd flashcard sets when my laptop was stolen, since they aren’t on my ankiweb account. Any help would be appreciated.

If you didn’t sync your data or back it up, there is no way to recover it.