Cardholder Services — Scam
Card Holder Services is calling across Canada from the USA (Petersburg, Virginia). They get around the "Do not call" lists because Canadian and US government agencies are too lazy to work together to stop this non-sense.
Do not give out ANY information to this company. At best they will charge you for something you can get free elsewhere, at worst your information will be abused. Either way, you lose!
Do complain in any way you can, but don't expect the calls to stop...