Did anybody else have a problem getting Netflix to honor the six month credit from Google?

Netflix may be trying to squeeze customers for extra months of service beyond their promotions by falsely claiming there is a problem with the customer's back-up payment method.  When redeeming the six month credit, NF demands customers give them a back-up payment method even though no money is due when they sign-up.  No problem with that, as it is standard with all promotional sign-ups from other companies.  But I ENDED UP HAVING TO PAY UPFRONT just to get them to accept my card and use the credit that came with the CCwGTV bundle.

I bought a package deal from Google for a ChromeCast with GoogleTV bundled with 6 months of Netflix for $90+tax.  When I tried to sign up for Netflix using the included NF credit, the NF website told me there was "a problem with my payment method".  I called my credit card company, Citi Card,  and they said NF NEVER TRIED THE CARD.  To be sure this was correct, I asked to talk to a Citi supervisor.  The supe guaranteed me NF had not tried the card, else there would be a record of it on my account.  He also assured me my account was in good standing.  Also, they had heard this same thing happening to other customers.  They said the problem was NF.

Called NF, they suggested I buy a gift card (minimum $25) and use that to sign up with.  Didn't want to do that as I was owed the $84 CCwGTV credit and likely won't keep NF after the six months. Tried five different cards from two different CC companies and got the same message,  "a problem with my payment method".

Now get this: when I signed up for a NF account w/o trying to use the google promotional credit, my payment method miraculously was now fine and dandy -- the same card that wasn't good as back-up payment when trying to use it to redeem the promotion! Only then could I get my six month credit.

I checked on-line and many other people reported the same thing when NF used to have the free 30 day trial, "a problem with [the] payment method"
Are they doing this to ensure they are going to get some cash out of people who sign-up using a promotion?  It wasn't like I was getting six months of NF for free, as the Google bundle cost way more than buying the Google ChromeCast by itself.  If I had had to buy the NF gift card to sign-up, they would get an extra $25 besides what ever Google pays NF, or they would get the cost of the extra month I had to pay to get them to let me sign-up and apply the Google promotion credit.