[jusben1369]

What may be happening there is that Netflix is connected to services provided by the card companies to stop interruptions to recurring billing for reasons like this. Long story short if Netflix receives an error code from the payment gateway that says something like "Card expired/Card changed" it'll make a call out to this service with the old card data. That'll do a look up and return the new data to Netflix who then updates their records and charges away happily.