I got a weird letter from The Domain Registry Network of Canada asking me to renew one of my domains with them for $40. I never even heard of this company and they are asking me for my credit card number. They also had all of my information with them too. What should I do?

What information do they have? If it's just your address, then they could have easily attained it from the WHOIS database.

Re-read the letter carefully and see exactly what it says. If you don't have the domain with them, then ignore it.

If it isn't the register you used to purchase the domain then as webfreak08 stated ignore the letter.

This is a scam.
Ignore the letters.

Or burn them for heat.
I get those all the time. This is off-line spam, and is getting really annoying.

I received mail from them back in 2000 when I lived up in Canada. It's a load of bull. (I knew because I had only just moved to Canada about four months prior; yet I received this shortly after moving my last domain away from Network Solutions.)