Anyone getting an ADSL/ADSL2 account with Telstra, based solely on my own experiences would absolutely need rocks in their head. Bigpond is fast running out of water, IMO!
They were much better when they were the PMG (Post Master General) - and nicer and easier to deal with too.
Oh. When you cancel the account make sure you insist that you no longer wished to be contacted from them, and include that you will not be interested in coming back to Telstra Bigpond (and/or phone) because of their poor customer service.
This will make the point about poor service you received - hopefully helping them to improve service. Furthermore, it will stop Telstra bugging you to come back to them once you have left.