I want to upgrade my nextel i580 to the motorola renegade, do i have a sprint account?

I currently have the I580 with nextel service, I have the Business Essentials 400 plan, I just signed up for it, I want the Motorola Renegade phone woth PTT, but I am told I have to have a sprint plan before I can get one, Is the business essentials plan a sprint service plan? I thought all new plans were both, and Im ok if I signed up recently to get a sprint phone with PTT?