I'm in a similar position as you. Recently moved in with my partner who lives in one of those flash new estates. Problem is that it piggy backs off an already over populated exchange (two other estates, which are still being built use it along with 30+ year old suburbs).
Telstra "Suggested" that the only way she can get any internet connection is with their expensive (dollar: gig ratio) wireless internet which is crippled during peak times due to the technological limitations the 3G (and 4G will have same issues) network has.
I have been trying to get her an ADSL connection for the last two years on and off. First went through Bigpond who gave a very vague reason as to why
and then in the same email tried to upsell their wireless plans. After some prodding by me found out local exchange doesn't have any free ports.
That was fair enough, at least I knew the problem and could just reapply over and over until a port frees up. Nothing new there.
Now being sick of being sent advertising material talking up the benefits of wireless internet instead of a reason of rejection decided to go through TPG.
I've had nothing but good experiences with TPG, have been with them for years at my old place. Decent connection, good customer service. Fire off an application only to get a response the same day (rock on TPG, you crazy ISP) to say that we can't get ADSL2+ but can get ADSL1. Great, that is certainly better than this abortion of an internet connection. Told TPG to set it up.
3 days later, get an email telling me that because Telstra has used a Pair Gain (You know, that out dated, ADSL blocking technology) on the line we won't be able to have an ADSL connection. But TPG would send Telstra a Transposition request. 1 Day later get another email from TPG with a single sentence quote from Telstra
"We are not upgrading the exchange in the foreseeable future"
Another wonderfully vague answer from Telstra that doesn't actually tell me anything about our situation. I'm down to trying to get a straight answer from Telstra or applying for a new phone line that isn't on a pair gain (Extremely unlikely, only seen it work once and wasn't in RIM hell).
My friend, I feel your pain.