Need help with my AC Unit?

Our landlord has had the AC men come out here 3 times yesterday. The first time, the guy sprayed something on the unit because he said it was dirty. He said that would fix it. Then our landlord came to ask us if the guys ever showed up. I told him they did but I wanted to show him the way it had been doing for about 2 weeks. It doesnt hardly blow anything and what it does blow is hot. When I went to show him, it wouldnt even turn on. So they came out again and flipped the breaker. It worked. But he wanted to bring the other guy back. So they came back later and the other guy notice how if u looked up in where the AC Unit is, u could see outside. There was no cap on the Fresh air duct. So he tied a piece of metal onto the plastic to close it off. (Keep in mind the AC Unit has been on since about 2 or 3 yesterday afternoon). So about 4:00 this morning when we were finally getting ourselves to bed. We notice how it was getting hot in here again (but the AC was STILL running) So we looked in there again to make sure the metal didnt come untied. And the Whole AC Unit had about an inch or 2 of ice ALL over it. We turned the unit off and then from the bottom of it, it caught fire and went out. With loud pop noices during it. We have not turned the Unit on since. It is one of the trianglular AC Units. The owners told the landlord yesturday that they told the guys to order a new Coil. But since all this happened, are they going to have to do more to it? Did the whole thing Blowed up? Its 90 degrees outside and we have a 2 year old daughter. It's burning up in the house already. I want to know how long it will take to get everything they need if they order it now, and what happened to the Unit at 4:00 this morning. Oh yea and, When the sparks/fire came, it had the most strongest burning smell in the house along with the whole house being filled with thick smoke.