Did the withholding show up on 1040 line 25b? The withholding is not the tax. It is just an estimated amount to cover any tax due. You still have to enter the whole gross original amount (before taxes were withheld) with your other income to figure out the total tax (and it may put you into a higher tax bracket) and then the withholding is subtracted from the total tax to figure your refund or tax due.
Are you under 59 1/2? There is an extra 10% Early Withdrawal Penalty.
