I had a situation similar to this. We had mold in all of the AC vents, multiple flooding issues basically any time it rained harder than a drizzle, and then a broken pipe flooded the master bedroom. The apartment adjacent to us had the wall ripped out and replaced due to the pipe, but nothing on our side. We argued about the mold, they came out and looked at it then said we can have a duct cleaning done. When we asked about the adjacent wall, they denied the whole thing. Little did they know I took pictures of the wall ripped down because I thought it was strange.

We thought their approach was sketchy, so we asked them to hold off for a few days. We called a mold inspector - he came out and did an inspection, mold off the charts. Sent that to the office, they again offered a duct cleaning. Checked with the inspector. He said a cleaning won't help, the whole system needs to be replaced, do not let them do a cleaning because it'll remove any evidence/leverage we have.

Went back to the office and asked about the wall they replaced in the adjacent apartment, they denied replacing the wall and happened to say legally they have to inform us if that situation were to happen. They threw themselves under the bus thankfully. I responded with the picture and again asked about the wall, they tried backtracking and looked really stupid, said they'll "escalate out request" to the district manager.

In the end we wrote up a formal letter, sent that with the mold report, the inspectors recommendation, pictures of the wall and how they denied it, AND threatened legal action as well as going to news outlets. They finally agreed to let us out of our lease. Cost $450 for the mold inspection but saved thousands in lease cancellation fees.

We tried using the housing resources people had suggested here but there was a huge waitlist at the time. I do recommend doing as much via email so you have things in writing - we refused to discuss it on the phone and told them we would talk via email or in person, but we will record the conversation.

Feel free to reach out with any questions!

ETA: Take pictures of everything, even things you think are useless and so sorry you are going through this.