You are still receiving your original refund amount. The net of the original refund and the amount
you owe now is what your original refund/amount owed would have been if the
1099-C was included in your original e-file.
Not knowing anything about your filing status, income level,
etc.; I can only speculate about the tax amount. The amount you now owe is approximately 25%
of the income you added. But there could
be other factors that are affecting your return. For instance, if you had the Child Care Credit
and/or Earned Income Credit, those credit amounts could have decreased due to
the increase in your income.