Tripped and fell at YMCA at private meeting, room was rented out, I was volunteering for a conference

Lights turned lower and I tripped on carpet. Left knee hit hard and froze. got ice from concession, they did not fill out accident report. I called later that week to manager who said he did. YMCA office advised they would not cover any Dr appts medical bills. Now the knee is hurting worse and keeping me up at night, i am limping. I have no personal insurance. We were not asked to sign a liability waiver until after the incident was duly reported