The transfer box on my Volvo XC90 has failed after four years and 46,000 miles. The Volvo dealer has quoted £4000 to fix the car and deny any responsibility for failure of the transfer box. Unwilling to pay £4000, I’ve taken the car to a gearbox specialist who found no fault with gearbox but found a destroyed transfer box fixed at a cost of £2800. The dealer has shown no interest in helping and doesn’t accept any liability for incorrect diagnosis and consequential losses. What should I do?