It occurs to me that you might try to contact the HSA custodian and report a $4,125 "mistaken distribution". If the HSA custodian accepts that (they certainly don't have to, so be nice), you will have to send them the $4,125. Then you can request the withdrawal of excess contributions (the $2,155 number this time) and they will send you the $2,155 back. NOTE that this all has to be done by the due date of the return (including extensions), so you probably want to file an extension just to give your self some time to do this.
If the HSA custodian is a good sport and actually allows you to do this, then you need to do only steps #1, #2, and #7. You will have undone the unqualified distribution, although you will still get a 1099-SA next year with the earnings (as you should).
I should have thought of this first, but since the HSA custodian is not required to accept requests for mistaken distributions, you can't count on this working. But it is worth a shot.
