Being sued by Cavalry Portfolio

I received a summons from Cavalry Portfolio stating they were suing me for about 7500.00 from a debt that they purchased. When I received the summons I answered it denying that I owe them anything since I have never heard of them. It appears they bought a debt from 1999 that was not paid on since 2001. The debt was with MBNA and then became BOA and then bought by Cavalry. I sent a request for production asking Cavalry's attorney to provide me with an original contract signed by me between the original creditor and I, an original contract signed by me agreeing to pay Cavalry anything, complete detailed accounting of the debt and payments, any communication between me and original creditor and/or Cavalry, copies of original documentation regarding how much Cavalry paid for the debt, etc., etc., etc. What I receive from them was none of the above. Cavalry sent me a response to my request objecting to all my requests. I responded stating they were necessary to validate the debt that I allegedly owed them. I then received an Affidavit of Account signed by one of their employees, a copy of an credit card agreement that is generic and copied off the back of a statement that could belong to anyone and does not identify me in any manner. Later I received an Affidavit of Claim by another employee stating that she had knowledge that this was my debt and that she could testify to that, a Bill of Sale with no identifying information about me specifically from BOA, an Assignment with not identifying information about me specifically and an excell spreadsheet that lists about 20 people who 19 of them have been blackened out and my name, social security number and an amount of about 7500.00 listed as owed with no infomation as to who created the spreadsheet or where it came from. None of this as I see it is enough to prove that I owe Cavalry anything. When I received the Affidavit of Claim.... I then sent the court a motion to strike all this information as it is not what was requested in the request for production, that the information in no way identifies me concretely nor provides a contract that I agreed to pay them with my signature. From that I learned that when they filed their Rule 26.1 disclosure that they did not provide the same documents to the court that they provided me and that they asked the court to ignore my motion to strike. I may have filed that a little to early since I am just going to the pre-trial conference on June1. But they still have not provided the documentation I have requested. I also did a notarized sworn affidavit of denial that I owe them anything and that if I do the amount is not right. I have learned that MBNA has written off 3/4 of the debt and left 1/4 of the debt as being owed and did this in the same time frame Cavalry claims to have purchased the account and that Cavalry now shows on my credit report as owing them the full amount. Somehow I think there is some illegal stuff on Cavalry's part but I don't know where to begin with that. Does anyone have any ideas, I know Cavalry has been fined because of their illegal actions that they do some underhanded things. I want to stay one step ahead of them if I can. If they can not provide the original contract with my signature or a contract stating that I agreed to pay them anything or the information that I requested with regard to how much they paid for the account which I know is not 7500.00, is there a chance that I can win