Modem Storage Overload?

I got the modem memory overload warning also. Seemingly triggered by six text messages that looked legit but we're not intended for me. I erased each one individually by touching the trashcan symbol after putting each respective text message on the tiny Gateway display. Warning then disappeared. No repeat in the 24 hours since. Gateway is assigned a local phone number, so I'm guessing I'm getting texts for a previous user of that phone number. I called support which said they'd call me back within 72 hours; they said they'd received multiple similar complaints. I'm guessing they'll find a way to block non-TM texts to the device.