Who is telling you this stuff? If it is a nurse, doctor, pyschiatrist, etc. see what their ethical duties are. In America doctors have the AMA and pyschiatrists have the APA. Read the codes applicable to your country. If they are violating their own ethical code report them. All professional associations should look into ethics complaints. The professional ethics committee will almost certainly be staffed by people outside of the hospital. That would put a fresh set of eyes on your diagnoses and what has been done with you.
In America if you tell a medical professional you want to hurt yourself or someone else it triggers a response. I am not sure but I think if they believe you (in America) they have to hold you.
...................
Are you asking them for drugs? If they think you are drug seeking that is a possible reason for them to refuse admittance. Anyway, check their professional associations ethics. If they are not in compliance, report it.