If it is the problem suggested, try and get the Dealer to at least get a 'goodwill' gesture from Nissan UK. Again, if it is the problem suggested above make the point that it is aknow fault on the 370 forums and given your limited mileage it seems a recall should have have been issued.
But no TSB or recall ......so far.
I had (another) search around on the US forums to see if there were any updates given they seem to have had a greater number of failures than over here. Pulling the fuse that controls the steering lock unit is a preventative measure and seemingly has no adverse effect other than the steering lock does not work, which may be an issue for some....
NOTE: THE FOLLOWING IN BLUE IS LIFTED FROM OTHER FORUM POSTS SIMPLY TO HOPEFULLY HELP MEMBERS ON HERE.
A picture of the fuse that matters (the fuse box is next to the battery):
You have to pull the fuse after you get the SLU to let the car go to ON or ACC. If the SLU is not making the microswitches properly, it does no good to pull the fuse.
If, like the OP, your lock try wiggle shaking and banging the crap out of it to jar it loose first. Blow a heat gun/hairdryer on it if its cold etc. You only need it to disengage one last time. Some have luck tapping it with a little hard object like a SMALL hammer or screwdriver. My understanding from reading various threads over the pond is that over-lube inside causes failure of some plastic bits and the little gear teeth fail then get hung up. Tapping might get it one last time, then once its unlocked you can pull the fuse and save a lot of money and a wasted day or two.
Sadly, replacement SLU's have also be known to fail!
But I really do feel that Nissan should be replacing a unit that is an inherent part of the car's security, even if there are no known failures (on the move) that have raised safety concerns.