Displaying the Incorrect Cost

My goal is to display the cost for a One-Day Conference on a web page, which is $50.00. However, I keep getting $0.00 in return. I tested my SELECT statement in SQL and it is retrieving the correct data. Now I have narrowed down the problem to be in my if...else if statements in the PayBackCC method but I am not certain. It should get the cost from variable cOneDCost. Any help is appreciated.

Code behind

protected void PayBackInfo()
{
    try
    {
        con.Open();
        SqlCommand PBCredit = new SqlCommand("SELECT * FROM PaymentInfo, ConferenceReg WHERE PaymentInfoID=PaymentInfoIDNum AND PaymentInfoID=@payID AND ConferenceReg.Deleted='N' AND ConferenceIDNum=@confID", con);
        PBCredit.Parameters.AddWithValue("@confID", confID);
        PBCredit.Parameters.AddWithValue("@payID", Request.QueryString["payID"]);

        SqlDataReader readerPB = PBCredit.ExecuteReader();
        while (readerPB.Read())
        {
            piID = readerPB["PaymentInfoID"].ToString();
            cID = readerPB["ConferenceIDNum"].ToString();
            poID = readerPB["PurchaseOrder"].ToString();
            partnersNum = readerPB["PartnersIDNum"].ToString();
            cFullCost = Convert.ToDecimal(readerPB["ConferenceFullFee"]).ToString("#,##0.00");
            cOneDCost = Convert.ToDecimal(readerPB["ConferenceOneDayFee"]).ToString("#,##0.00");
            partnersCost = Convert.ToDecimal(readerPB["PartnersFee"]).ToString("#,##0.00");

            PayBackCC();
        }
        readerPB.Close();
    }
    finally
    {
        con.Close();
    }
}


private void PayBackCC()
{
    if (!partnersNum.Equals("null") || !partnersNum.Equals("0"))
    {
        msgLbl.Text = "$" + partnersCost;
    }
    else if (!cFullCost.Equals("0"))
    {
        msgLbl.Text = "$" + cFullCost;
    }
    else if (!cOneDCost.Equals("0"))
    {
        msgLbl.Text = "$" + cOneDCost;
    }
}