Hmmm... that doesn't sound right to me. I'm sure others may chime in, but my understanding is that Amex no longer gives a pro-rated refund of an annual fee if you choose to close the account during a membership year (they used to). They will give a prorated refund if you downgrade a card, but as mentioned, the Schwab Platinum card can't be downgraded.

So I don't think this is possible unless they make an exception for you, based on your circumstances perhaps, or if they handle a Schwab card differently since it can't be downgraded? But I'm betting on no prorated refund.

Regards