At work I'm covered by an HDHP with an HSA. My dentist has the policy of estimating the amount that my insurance will cover and asking for the remainder at the time of service. On my most recent visit, the office grossly miscalculated the amount that my insurance would pay and ended up charging me more than they should have. Now that the insurance has paid their portion, the dentist owes me a refund of the overcharge.
If I've already sought reimbursement for the original amount of out-of-pocket expense from my HSA (it's a qualified expense), what do I need to do (if anything) to make the HSA whole? I'm assuming that this can't be corrected by an additional contribution. Is there some form of excess distribution (the converse of an excess contribution)?
Possibly related: Can return fees be reimbursed from an HSA?