Rogers → Registering SMCD3GN from US ISP

I sold an SMCD3GN to a Rogers customer a couple of weeks ago. He followed the steps here to get his modem added:
»[Extreme Plus] How to add Motorola DOCSIS 3 (SB6120 or SBV6220)
Of course indicating that this really is an SMC Networking Device. Rogers Fulfillment flatly refused to add the modem on at least three occasions. Twice on a Sunday with no management around, but once more on a Monday even after escalating to a manager of some sort.

I was on three way calling with the customer on two of those occasions, as soon as we gave the MAC they said "That isn't in our database, go away". I said that of course it wasn't in their database, it is from outside Rogers network, so add it to your database. They flatly refused. We had to give up, and I refunded the customer.

I have had a handful of customers successfully register my modems for use with Rogers over the years. Unfortunately it seems as though something has changed. Any ideas about what's going on?

Rogers does not officially support any modems that are not purchased by them. Therefore not all reps are willing to break that policy and register modems from other sources. In addition, there is no official way of adding 3rd party modems, those who know how to do it have figured it out by toying with the system and using various workarounds. Not all reps have had the opportunity to do that, or are not willing to risk disciplinary action to put that knowledge to use.