Those are usually thrown away, not repaired.
If a storage device (any storage device) contains important info, it should be backed up. That's a quite simple rule of thumb. If it contains really important info, it's advisable to have 2 backups.
Now contact Sandisk or http://www.drivesaversdatarecovery.com/devices-supported/removable-media/ for their repair and recovery options. Given the age of the stick I assume there's no warranty, so it won't be free. It's up to you to consider the value of that data in relation to quote for the recovery.