Generally I don't expect much service unless I need some clarification on certain products, or charges.
So unless the bill for GST has been table and passed in Parliament, consent and came into force...
Otherwise I don't see why I should pay that extra 6.5% of unknown tax.
And that annoyed the hell out of me.
Sent the management an email alongside with a public posting in their facebook page asking for justification. I'm probably one of those bad clients that these corporate will want to avoid messing with, especially when I'm pissed.