Hi raysta101
Most of the items are disputed when it is regarding Palisades, AT&T or cingular. It is possible that different CAs can attempt collections but only one agency can collect for an account at one time. Two different agencies cannot collect for the same account.
To make sure that the CA is having your legitimate account details, ask them to validate the debt in writing so that the original creditor is identified along with all account information.
You must send this request in writing through certified mail with return receipt requested. Doing this, you will be sure that the agency has received your request and need to provide you the proof. If they fail to do so, you can explain the situation to the credit bureau reporting them. They will run an investigation with the CAs and the OCs and get the accurate account details. Once the details are verified, it will be posted in your credit file.
Don't make any payment agreement until you have review the account. Also, this debt might be out of the SOL period depending upon the date of last payment activity. So, you must check the state laws before making any commitment.