If the account is open, can I dispute it and will I still have to pay?
You can successfully dispute it. Sometimes removing it can be a little harder, but it is definitely possible. Even if it is off your credit report, you MAY still have to pay. The creditor or collector may still try to get you to pay. In my opinion, (not legal advice) I would not pay a collector or creditor unless they show you an original signed contract proving the debt is yours. IF YOU ARE SUED GET A LAWYER ASAP.