As someone whose service has been suspended three times due to future-dated plan change errors, I would like to suggest phones that are suspended, at the very least, still permit incoming calls for "x" number of days - giving Public mobile time to sort out the issue without completely compromising what may be the only form of communication for some clients.
I understand that paying the difference and waiting for a credit is a temporary solution, however, I don't feel that's something that one should "have" to do because of Public Mobile error.
