This is funny to me as my family members have had similar issues with new JD tractors and had to fight to get them fixed in a timely manner. It turned out the shops mechanics were not up to the task at hand and had to have a specialist flown out to diagnose and fix but it was worse than pulling teeth trying to get things solved.i hate to seem the doomsayer but i would back up the money bus return that thing and go get a deer or kubota, i dont know the KIOTI and it may be a simple fix and leave you with a good machine...OR it may be a lemon, either way its a bad start to the good experience of having your own tractor and for sure its a bad sign when you buy brand new off the lot and now they dont have time for you.
Like others Seem to be hinting at, this sounds like something simple that the mechanic might be Missing but the dealership is not stepping up to the plate. That is not a brand specific type of problem and not unheard of from any other brand including kubota and JD.
Therefore only if his options for a better more ethical dealer are better with the other brand would he be better off!