@nkeeley100 I'll do my best to help you 🙂 Can you tell me if this came up when you were looking at adding a new number/phone rather than going through an upgrade option?
@nkeeley100, I had logged off by the time you posted but I'm here now. From what I gather from the info you have provided, you are on BillPay right? So if your were looking at Prepay via your My3 upgrade option then it would say "you’re not allowed to purchase a new subscription" as it's not compatible with your plan. When you check a BillPay upgrade option this should happen.
If you'd like to check Prepay phone prices, please log out of My3 and then check the online shop 👌