Portfolio Recovery Associates LLC Offering me a settlement on a credit card I never had Norfolk, Virginia

I received a letter today from Portfolio Recovery LLC saying that I owed Bank Of Omaha about $700.00 but they would settle for $300.00 and this is the first time I have ever heard of this compay and I have never had any accounts with this bank. As of 10/2009 my credit report showed no delinquent accounts and no negative marks and I have a excellent credit score. I pay my bills on time each month and since I obtained my latest credit report I started getting letters saying I owe several different banks, but I have never had a account with any of them. I started reporting these collection agencies to the BBB where they are located, and I ordered a copy of all 3 of my credit reports from the 3 large credit reporting companies. These debt collectors are saying that these debts are all 5 years old, that seems strange that they all would be 5 years old, and I have never heard of them. Why would they wait 5 years to suddenly start offering me these settlement offers without ever contacting me before? I opened a credit acct with BOA for $10,000.00 last January and they require excellent credit. Now these companies are trying to extort money from me saying that they will report me to the credit reporting companies and lower my score if I do not take their settlement offer. I will not back down. These places are scams. I have been at the same address since 1989 and I have had the same phone number. I would welcome any comments on my situation as I fear that I have been a victim of ID theft.