i think to be llegally covered you need to have the dealer attempt to fix it several times. Phil responds well to legal threats, he backs down easily. when you go there and ask them to look at it again, and repair it. just be calm, dont make a scene. write down every time the car has to go in, what they do. ask for a service sheet of what they have done.
also dont pay a cent, its clearly a warranty issue.
if they cant fix it after a few times, ask him you want a gearbox specialist to look at it, he will probably arrange to have a workshop he deals with to look at the car. try that. if you get it repaired yourself, youll never see the money unfortunately.