If you have not yet picked up the car and are planing legal action.

Document everything including pictures.
Send it to the General Manager and Service Manager and Attorney General including picture.s REGISTERED MAIL.

Close with details of what and who from Clare wants you to do.

ie. pay the bill before the keys will be returned (I'd use American Express) then cancel due to failure to complete service)

If you fail to document it can become "he said, she said."

I feel for you. I went through this with a new Buick years ago and it was only weeks old when issues started.