singtel 
I called in this morning cos my phone line was constantly called
up and went dead when i picked it up.
The cust service said this is very common these days
and its usually cos some idiots sets ur
number to auto redial on their fax machine.
So i explained to her that its a business line and i cant be
picking up the damn phone every 3 mins. she said will transfer me
to their business dept where someone can check the number and
advise the other party to stop faxing me.
i was left hanging for like 30 mins while waiting for them to
pick up a transfer line. then the other person tell me that :
1) i hafta pay to trace
the call.
2) or pay to do a line
transfer to my hp so i can see what number is calling (not
guaranteed).
3) or pay to install
caller ID (not guaranteed).
i was rikes wtf. some idiot set their fax line and i gotta pay
to stop em ? 
so i asked her if she cant just checked her database and just
sent a note to the asshole on that line. and she claims that
singtel doesnt keep any records !
so in this case, the consumer is just farked lah ?
#@@$^#$#^%&#%^&#$^^$^[email protected]^%@$^#$^&#^$
I get that sometimes too ..
Caller ID doesn't say anything ..
Sometimes its "withheld"