Welcome, sorry to hear of your problems, could be an idea to contact Jaguar directly and explain the situation, also could be worth telling the dealer that you are not satisfied with the way they have dealt with your complaints and that you are taking it another dealer, but at their cost, also could worth saying the dealer that you are contacting your local trading standards officer at the council, that the car is not fit for purpose, due to the amount of times that it has gone back to the dealer and problems still not resolved, good luck.