Expired .Cab files not deleted

I have 4 vaultstores. No sharing enabled for all stores.
The below partitions have some .cab files left (between 4 mb - 31 gb). 
Most expired items have been deleted by storage expiry.
The last modified date is in brackets. 
The retention period is 3 years. 

Can anyone provide some insights why these few leftover files are not being deleted?

G:\Enterprise Vault Stores\JournalExchange32 Ptn2 (2010)
G:\Enterprise Vault Stores\Journal2010A Ptn6 (2014)
G:\Enterprise Vault Stores\Journal2010B Ptn5 (2014)

H:\Enterprise Vault Stores\JournalExchange31 Ptn2 (2010)
H:\Enterprise Vault Stores\Journal2010A Ptn7 (2014)
H:\Enterprise Vault Stores\Journal2010B Ptn6 (2014)

I:\Enterprise Vault Stores\JournalExchange32 Ptn3 (2010)
I:\Enterprise Vault Stores\Journal2010A Ptn8 (2014)
I:\Enterprise Vault Stores\Journal2010B Ptn7 (2014)