Manually deleting file system snapshots on Unity

I am trying to free up some space on my Unity 300 and I see that 5TB of space is being used by 22 snapshots of my file system (schedule is to perform a snapshot every weekday and retain for 30 days). I selected the 10 oldest snapshots and tried to delete them but now they seem to be lingering in a "Destroying" state and neither the number of snapshots nor the space used has gone down. It's been several hours. Snapshot auto-delete for the pool is ON. I only have file system snapshots, nothing for LUNs or VMware datastores. Any advice for kickstarting the snapshot delete process?