Smoo
There is a company in bournemouth who offerred to do it for me for £80
i am in the same position, my dealer promised me it worked but after order i discovered the issue.
I am just going to do it myself when i get the car. Ignore the dealer threat re contract etc. They are highly unlikely to check these settings on service and even if they do they will just reset it and you will need to do it again.
Just be brave and change the setting yourself, once the dealer has their money and you are motoring just dont mention it again. D0nt be so honest