http://hangyong.livejournal.com/88054.html
Take a look.
Be sure that overdeduction does not occur often or everyday.This
system is not a fool-proof one.
Do the claims even if the sum is small, if you do not stand up to
the mistakes, it will never be corrected.
If not for the concession pass, I would have reverted to cash
payment. 
I simply do not trust
the firms here to be entrusted with proper deduction of money.the
EZ-Link system entrusts money from your card to the firm for the
time in between embarkation and disembarkation.This overdeduction
is potentially a criminal breach of trust if it's not solved.
