I had the following response to an email I sent to T-mobile asking them to clarify my plan. I have not altered it in any way, I am grateful for anyone else's take on this.
-Thanks for your email about the half price plan rental.
I'm sorry to hear that you're not aware about the details of half price plan rental.
I've checked your account and I'm please to inform as you've upgraded your phone and was offer the handset free of cost.
You'll not be receiving the half price plan rental on your contract.-