CAJ1, you might as well write to E.T.
i can tell you now, the hospital WILL reply, then fob you off in every way that is legal.
ive been there. attempted to make a complaint against a Doctor i felt was neglegent to my son. after a couple of weeks i received a "its being investigated" letter.
weeks later a follow up letter informed me the Dr involved had left the country. not 100% sure of the details now but it was something to do with him not being employed by the local authority....
amazingly i saw him a month or two later in town !
i wish you luck, but i doubt you will get the responce you are looking for.