The credit or TTV (ticketless travel voucher) is linked to that confirm number.
All you need to do to use it is have the Purchasers name and the TTV number to use that credit with-in one year from purchase date.
So yes you could infact use that credit for future travel ,You can't get a cash refund of the difference,you could let your company know of the credit so they could use it for their next booking .