AllianceOne Receivables Management review: debt they say I owe

I was contected by Alliance One about this debt and I was told that the last payment was in 2005. They have my name and address and ph number. I was told by them that they would settle the debt for $250.00 if I sent them the payment within the next 24hrs. I asked where and when and what store I used this card. They could not give me an answer. Nor would they answer any of my other questions. I have paid all my cards on time and I ask why would I not pay on this card. To the best of my knowledge I never used this card anywhere.
I am retired and live on a fixed income.