The NSF check function is indeed inactive if the deposit was reconciled and posted. How soon after the deposit was entered was it reconciled? How soon did you receive notification that the check bounced? Choosing to post a reconciliation indicates that the check has cleared the bank.

As for reversing the customer payment, is the invoice(s) paid by the bounced check still in Current AR Transactions, or have they been cleared to History? The answer will affect the required solution.

If they are, then you can create a cash entry with a negative dollar amount, and apply the negative amount to the invoice(s). This will reset the invoices back to the current amount and generate the appropriate GL transactions.

If they are not, then you have to recreate the invoices in AR, and also create journal entries in GL and a dummy batch in BR to correct the bank balance. Others reading this post may have other suggestions for you.