I received a bill from a debt collector that I can not remember obtaining, and if I did have this debt the amount is far above what the limit was. At the bottom of the bill it says "The law limits how long you can be sued on a debt. Because of the age of the debt, we will not sue you for it, we will not report it to any credit reporting agency, and payment or non-payment of this debt will not affect your credit score". What does that mean? If it does not effect me in any way why should I pay this request?