"No appointment"

I turned up for my appointment at 10am. I was signed in and told to go and sit in the waiting room. 45 mins later I thought I better ask when I'm going to be seen as people was coming and going and I'm still sat there, also I'm diabetic and need to get food if I was waiting any longer. I was told that I'm sat in the wrong place and had to go to day care where they weighed me and took my height. I was to be prepped for an operation. I'm not in for an operation and they couldn't find me on the system. I was taken back to reception to be told there was a mess up and I don't have an appointment and it go way and they will contact their manager and someone will get in touch. I've already been waiting 18 weeks for a appointment. I also paid a bus fare to attend the hospital.