It seems Slingshot is getting cornered - too many customers complaining about quality of services or customer service received.
TUANZ has called the Hon Steven Joyce, Minister of Communications, to the task, by asking the government to make it mandatory telcos and ISPs join the TDRS. According to their blog it's time to get serious about dispute resolution:
"What is lacking is a clear direction on funding for the scheme. TUANZ is fed up. We're fielding calls from disgruntled (mostly Slingshot) customers, on a regular basis. They're not covered and they've got nowhere to go."