How to cancel Norton subscription?

My mom's computer had Norton (360?), we removed it succesfully, but norton still sends us bills to pay. My mom has a Norton account, but she has forgotten the password. My mom has also got a hotmail address, where the lost password would be sent, but it's password is forgotten - also the password change is forgotten, and it doesn't have any secondary emails.

What should I do?

 

Is there a customer service phone number on the bill? If so, try that.

If you can't reach a person to explain the situation, here are 2 numbers that supposedly will get you a live person to talk to.
Symantec 800-441-7234 Press 00.
Symantec 800-745-6061 Press 5 after the prompt.

Good Luck (and don't pay the bill until you talk to someone.)