Keep hammering them. Make them swap out the cards, send a tech, whatever it takes. I went through 20 phone calls, five truckrolls and one FCC complaint. Every step of the way the excuses were:
It's your wiring
It's a problem with the Samsung box, call them
We don't support CableCARDS for anything other than local channels.
It was not my wiring, it was not the box and they're REQUIRED to support CableCARD devices. They just don't want to. They'd get it straightened out for a while, then at the first of every month, both boxes would go out and I'd have to start all over, again. I keep a log of every interaction and sent the whole thing to the FCC. Two weeks later, I got a letter from Bright House CC'd to the FCC and my devices have worked just fine since. Granted, one of them can't find WiFi to save its soul, but that's got nothing to do with the CableCARD.
Walking the fine line between jaw-dropping and a plain ol' yawn.