HI AuPhantoms,
It's disappointing to read your feedback regarding your recent experiences with us.
In relation to the plan issue, if this has been incorrectly changed, you just need to ask our 24x7 Support team http://tel.st/hsc3 to put you back on the 1TB plan you initially requested.
Our Team can also provide you with information regarding the speed boost. https://crowdsupport.telstra.com.au/t5/General-Internet-KB/Broadband-Speeds-ADSL-Cable-NBN-and-Velocity/ta-p/42335
Kind Regards