You would have to get into her account. If you do not now email/password, contact agent and explain situation.
You have to remove autopay and to ask agent to remove her credit card info. Nothing else is needed as account will go into suspension on next renewal and be deleted after 90 days of no payments. You can even declare phone lost/stolen and suspension/90 days counter will start right away
If you can find somebody who would take over her account that will be beneficial for other person particularly if she had old rewards ($).
And if you can find somebody to take her phone number, porting out number deletes PM account immediately.
@tanyarussell58 I'm so sorry for your lost.
Did she have auto pay? If she did then send private message to customer service: https://productioncommunity.publicmobile.ca/t5/notes/composepage/note-to-user-id/22437
You could call your mom's credit card company to stop auto pay to her phone service.
If your mom did not set up auto pay, then don't pay to her plan, her plan will be suspended and after 90 days her account will be closed automatically.
@tanyarussell58 Sorry for your lose. You'll have to get help with that from a customer support agent.
Send a private message to CS_Agent
Even if she had auto pay, you'll still want to contact a CSA to have them remove the CC information, totally from the account. To avoid possible future charges.