caller said nothing

I got call from this number i think there is a group of telemarketer calling from pakistan or india whn they donot get anyone they swear

This number has called multiple times the last couple of days.  Mostly shows up as 'unknown name', but did come up one time as 'sialk.ca' who appear to be a long distance reseller.I finally did answer a call since the constant callbacks were annoying.  A woman asked for me by name and told me that Yak Communications asked her to call to give me a special money saving offer.  I cut her off indicating that the phone muber is on the National Do Not Call List, and asked they not call anymore.  Hopefully they will stop calling.

Call from (416) 555-7777 (unused number) then hangup.Caller id was "sialk.ca"The CRTC will be involved next time. My number is on the "do not call" list.

Got a call today and someone was just breathing.  I tried to call it back and number is not in service!  pretty wierd, i called bell and they said it is not a registered number but it might be an online call from skype or something

I have received about 25 calls from this number in the last 24 hours. Some foreign (Indian?) guy saying, "hello, hello, hello" in every message and trying to say some other stuff, but I couldn't understand any of it. I'm glad I googled this number and got this site, so I know I'm not alone. This is so annoying and creepy. Is there any way to track these a**holes down, or at least block the number?