Debt no longer with recovery company still covered by DRO?

Hi. I came out of my DRO this month but have realised one of the debts haven't been included. It is past the 12 month period FYI. Initially I had a debt with an energy company. Some of the debt was held with debt collection company and when it came to the DRO I listed £x with them and £y with the energy comps details. So supposedly only the amount that was listed for the energy company has been settled which was for more current arrears. So basically what was being asked for in total was split up between the two. I have managed to find out that the debt was passed back to the energy company before the DRO was started. So even though it was held by that recovery company it wasn't at the time of DRO. As far as I recall I didn't call the recovery company to check when I started the DRO. Is there anything I can do about this and in any way could it still be covered? I still used the same account number but like I said it seems to have been back with the original creditor at time of DRO being approved. In hindsight I should have done things differently but there were a lot of debts to juggle so mistakes may have been made. Any help or advice on this would be appreciated. Thanks.