collectors calling on old cc debt and don't know what to do

i started getting calls from a collection agency recently for an old credit card debt. I was told by the original cc company long ago that someone had used my card to call out of country or someone had called FROM out of country..can't remember which it was and that's what this debt is. i was naive and didn't follow through on it..just thought they were taking care of it and evidentally did not. next time i heard about it i contacted the cc company and they said it was my problem (in 04 or 05). I didn't have the money to pay the 200 some dollars so didn't. in 2006 i got a call from a collection agency and i told them the deal and said i didn't owe it and they stopped calling, however, i just looked at my credit report and it says "date placed for collection 09/2006" SO my question is...do i try to get the collection co to verify the debt? or do i find out when the last actual payment was made because i'm sure the SOL would be met. if they go from the 9/06 date depending on if they go by my current state i live in i would be done with the SOL, if they go by the state i opened the cc in i would have 2 more years, if they go by the state i lived in when this debt supposedly occured i would have one more year left. I just don't know what my best, smartest option would be. Any help would be greatly appreciated! by the way, the balance is now at 400 something with the interest but this collection agency said they would settle for 110. i told them i wasn't going to pay cuz it wasn't my debt and haven't answered any of their MANY calls since.