I was told orthodontic treatment would be free for my missing dentist but now they say it’s not. Can you advise?

Q.
Hello! I have a missing lateral incisor and a crown on the other lateral incisor. My canine has been scraped small, so they could try to fit one big false tooth there but I refused because it looked weird. This procedure was made in Africa in 2008. Now I have a missing tooth and a crown which is starting to smell!!!! I went to my local dentist for a check up and asked them to remove the crown. I also asked them to refer me to the orthodontist but he refused to remove the crown. The reception gave me the orthodontist’s number. I called them and asked them to give me an appointment. They said because I was 20 years old that it was not free but told them that I have a HC2 form but they said it was private appointment . A dentist told me that the procedure would be free because I had a missing tooth!!!! please help? Is this right or wrong? Will I get a free treatment because of my missing tooth? If I have to pay for braces how much will it be? By the way I have not broken or damaged the missing tooth. After my baby teeth fell out x-rays should no lateral incisor on my left side and a very small lateral incisor on my right side(which looks like a baby teeth but now has a crown).