Hi Pennyjm,
Thanks for getting back to me!
I stand corrected as Toowoomba falls right on the border of Energex/Ergon service areas. Because of this, the idea of your neighbour being billed by AGL and yourself being billed by Ergon is feasible. To determine definitively if your address can be billed by another company, I encourage you to have a chat with Ergon's customer service team. They can be contacted on 131 046 (7am - 6:30pm Monday to Friday).
Please let me know if there is anything else that I can do to help!
Kind regards,
Jayden