Get your taxes done using TurboTax

By law the IRS cannot pay the CC merchant fee so if you pay by CC  you must pay that fee ... the IRS doesn't get that money.  And as with everything else you must READ the screens before you agree to proceed ... that fee was clearly posted and you could have stopped at any time up until you hit the final button.  

Note the IRS also posts the fees most clearly ...  https://www.irs.gov/payments/pay-your-taxes-by-debit-or-credit-card