It's my experience that other than the activation e-mail message, Public Mobile never e-mails customers anyway, so I would say to just block the e-mail address. This may seem extreme, but it's an option that doesn't rely on someone else to fix the issue.
Honestly, whenever there are any changes to Public Mobile policy, customer service contact method changes, or even price changes, the notices have always been given by text message and through the Announcements forum, and NEVER by e-mail, at least from my experiences of 2 years as a customer.
