Hi Mohammad,
What I understood is that you created a new model, no transaction data and no other configurtion done, now you want to delete the model, but you are not able to. I hope you there is no security issue, if there is no security issue as well, I would suggest you raise an OSS message and let SAP look into it.
Of course, you may try to delete it from backend BW, but it is not recommended, so let SAP look into it.
Regards,
Kalyan.