The cost to upgrade is on your dime.I have a car for 5 days, with map version 26.1.9755 and I see through the updater that there is a newer version 26.3.9846.
However, in order to download it I would need to pay $120USD.... Is this stuff covered under warranty? My dealer is clueless....
Don't go to service - they will charge you for the upgrade plus installation labor.
Go visit your Parts dept and pay them - they will then register the purchase with JLR.
If you ask nicely, the parts person may just perform the update for you....