I apologizes for the inconvenience caused. We will check the status and update you shortly and for more assistance please do reach out to Arris.com/consumersupport

Two months after my original inquiry, asking the status of my RMA, I get a response telling me - we’ll look into it. I will not be doing business with Arris in the future. 

Upon checking the RMA status, it shows that the replacement unit has already been delivered. For more information, I recommend visiting www.arris.com/consumersupport for further assistance.