rav 4 towbar

Hi we bought a rav 4 2004 to tow our Elldis oddysey but the ball is set too low and the jockey wheel hits the road on occasions.its a fixed one and set low so the rear door opens .

i am trying to locate the detatchable unit to fit the current bar so that i can raise the height and be able to remove the ball when i need to open the rear door, alternatively a new towbar with detatchable hitch ... anyone had the same problem??