Rollback to Plesk 9.2.1 Key

[DanielB85]

Hello,
we have a Plesk 9.5 License, but i make the mistake to upgrade the License Key before upgrade the Software, we had Softwareversion 9.2.1 and now, i didn´t come in our old Plesk 9.2.1. I ask the support of our system (strato), to give me the old 9.2.1 License, but the support of this version is discontinued.
Please help me, to become my old system back.
thanks