Complaint Review: Shelco Credit Systems

I had recieved a letter in the mail from Shellco Credit Systems claiming I had owed $13411.26 in damages to a Townhouse that I lived in for 7 years. There was no file number on this letter but I called to speak to the identifying officer that was on the letter, a "Mr. George" When I asked how possibly could this be, he yelled at me, argued that I had left the premises in complete mess and before I could continue even further, he hung up on me. I recieved another letter stating that LEGAL PAPERS were prepared and that the "final decision rested in my hands" before it went to the courts. I again called back, spoke with Mr. George who I informed that I had contacted a lawyer and that I was willing to go to courts but needed information on when the court date was as I had not recieved any other letters or informtaion in the mail for months he hung up on me and woul not give me any information.. One week later he added this over $13000 debt to my credit. So now I have a credit report saying that I owe this money and we have not even went to court yet so I could dispute it. When I called back for the third time just today he told me that he was willing to settle with a lump sum of $4000 I said I had not rev=cieved any ofromation regarding this in the mail, he said it was "bullshit" and that I had 3 days to pay this. I of course wasn't willing to settle as I disagreed with this owing and again when I tried to speak furthur about my case he once again hung up on me. How can they say I owe $13000 but then agree to settle for $4000??? It's insane.How are people even supposed to "solve" disputes like this if they are going to get sworn at, yelled and and repeatedly hung up on?? I was told by Equifax that Shellco Credit Systems were responsible for taking this off my credit so now I am just supposed to wait around for a court date that I may not even be notified about until I can go forward with the removal of this debt?? it's insane..