The Jaguar S-type transmission is filled for life and does not require servicing or topping off unless the transmission is leaking, or undergoes severe use. Severe use calls for a service interval of 30,000 miles. With 9000 miles after 4 years, I don't think you qualify for the severe use interval. I wonder what the dealers rational was? If the transmission is ever serviced it's essential that you use the correct fluid, Shell M1375.4. Hope this helps.
Mark @ Katzman Automotive and Transmissions
www.katzmanauto.com
23035 Douglas Court
Sterling, VA 20166