Had spoken to a cso saying the 20% pay as u roam applies only to
the roaming on the wrong network. But I was not forewarned on this
when subscribing to the pakage.
http://info.singtel.com/roaming/travelling-overseas/data-roaming
look under notes, item 2
When you subscribed to the package you already knew you had to
be locked to one network for the data roam service otherwise the
prevailing charges would apply.
No one needed to warn you, because its stated clearly in the
terms and conditions that you should have read when you applied for
the package.
And having used it myself, if you logged on to the wrong
network, a warning sms would be sent to your device almost
immediately of the consequences, unless it happens to be an ipad
which cannot recieve smses (WTF).