I have had nothing but problems with my current landlord, can my lease be broken without paying to break my lease?

-A week after I moved in, I was told that there were additional paper on my lease that needed to be signed. I haven't signed any additional papers, but all of a sudden there's no additional papers. -My landlord is saying that I have an insufficient funds charge for my apartment application, but there was enough money in the account for the fees. -I was told I was to be given my mail key the Friday after we moved in. I had to write a letter and go demand my key from the office in order to get it. -I also wrote them a letter on July 6th, which went completely ignored. -I am not sure if this will help my case, but my apartment is located on the third floor, and since moving in, I have had knee and hip pain, and I am only 19 years old.