Yet you accepted delivery of the P90D, which voids the swap for $10,000.
Unless you have something in writing from a Tesla executive stating that they would allow you to accept delivery on the P90D and pay them $10,000 later for a 100KWH battery upgrade, then you have no case. You would have to pay $20,000 if you want the upgrade.
As I said, why didn't you just take the $10,000 offer when it was valid - BEFORE accepting delivery of the P90D? I would have. I accepted delivery of my P90D just 2 weeks before they announced the P100D. I surely wasn't going to pay $20,000, but I would've paid $10,000.