I have received at leat 15 calls from this number in the last week.  I tried canada411 and 411.com both have no record of the number.I then blocked my own number and called it back - it is a "marketing' company calling "on behalf of" Bell Canada.  There is no option to have you number removed but does allow you to leave a message telling them when they should call.  I have left 5 (FIVE) messages telling them NOT to call again - yet the calls persist. There must be some remedy.

3 times a day for the past 3 weeks

Bell-Canada CAN put you on their OWN Do not call list.

Bell will first try to tell you to
register at http://www.the-cma.org/  
Do not register. You can block sales calls at this site by NOT ticking off mail, only put in phone and fax blocking which means you don't have to put in any personal information other than a single letter in first and last name. Put in all your numbers and you are then on the Canadian Marketing Association's do not call list supposedly up and running in the "fall of 2008".
If you want to block "spam postal mail" you can put your address in there.
What is a concern of course is that the numbers registered will be grabbed by an overseas VOIP service and used to spam from overseas.

Every day they calling three times...stop calling plz, I am so oooooooooo busy

(905) 297-3663 "Call-Net Communications. Hamilton, On" you can try call me 20 times a day.  as long as i see this number showing on my caller ID....i ignore it.

they call all the time  next time i think i will keep them busy talking to them