Question regarding multiple issues: No heat or hot water in winter and lack of state business licens

Hello there!

We recently moved out of an apartment on April 15, 2023. Our lease wasn't up until April 22, 2023 and we forwarded our mail on April 21, 2023. On May 1, 2023, we received a notice from a collection agency stating that we owed our previous apartment almost $1,200. There was no disposition of security deposit and no itemized receipt. When I emailed to ask why we did not receive a disposition, the property manager said he must have forgot to do that and emailed it to me. It had several erroneous charges and once I asked about them they said it was an "error" and removed the charges and stated they would send us a refund check.

Second issue, last November, from the 10th through the 17th, we were without heat or hot water. This had been an ongoing issue to which we had emailed, called, and sent in multiple maintenance requests to have the issue resolved. They would always put it off as if it wasn't a big deal and we were paying $2500 per month in rent so it wasn't really in the budget to stay in a hotel for 8 days. We also have 2 children who are 4 and 9. They would send their maintenance man who was unqualified to deal with heating and hot water systems and it would work for about 24 hours and then go out again. At one point I even asked if there was another unit we could shower in to which they did not respond. I finally threatened legal action against them and that's when they sent a professional heating company to temporarily fix the unit, but it was not replaced until December 22, 2022.

For the third issue, upon researching their business licenses to determine their DBA and entity name information so I could file in small claims court, I discovered that they did have an active business license in the city, but their state license under the same name had showed "Entity Status: Cancelled" as of 11/30/2022.

What are my legal rights? What should I do next? Are they operating illegally because they do not have a valid state license?

Thanks for any and all help!