It sounds like that GP was treating you as an irritation and an interruption to his work, when in fact you, and your health, WERE his work.
GPs are paid per patient on their lists, and some of them really couldn't care less, as long as they get the money. It's your taxes going into that bloke's bank account, and you were entitled to proper treatment.
Don't worry about being blacklisted - it's your right to complain. These are people in OUR employ, and we have a right to expect them to deserve it.