Is Telstra standard copper or is it the new Telstra Velocity fibre? If it is, well hate to be the one to tell you but your up shit creek without a paddle.
Velocity is currently not wholesaled meaning only Telstra operates service on it and as they don't run standard copper you have no choice but to pay the extortionate rates they charge.
If it's standard copper then check out amnet -
www.amnet.com.au