SQL query not working with the below code...Please help

I have the below stored procedure and C# code.

Stored procedure:

ALTER PROCEDURE [dbo].[ItemDetailsPicker]
AS
BEGIN
	-- SET NOCOUNT ON added to prevent extra result sets from
	-- interfering with SELECT statements.
	SET NOCOUNT ON;
select pop.itemnmbr,cast(round(AVG(pop.unitcost),2) as decimal(10,2)) as cost
from AFS.dbo.POP10110 pop
where pop.REQDATE >=DateAdd(day,-14, getdate()) group by pop.itemnmbr
END

C# code:

protected void BtnGetErPData_Click(object sender, EventArgs e)
        {
            string confirmValue = Request.Form["confirm_value"];
            if (confirmValue == "Yes")
            {
                string afsconstring = System.Configuration.ConfigurationManager.ConnectionStrings["ApplicationServices"].ConnectionString;
                using (SqlConnection con = new SqlConnection(afsconstring))
                {
                    using (SqlCommand cmd = new SqlCommand("ItemDetailsPicker", con))
                    {
                        cmd.CommandType = CommandType.StoredProcedure;
                        con.Open();
                        cmd.ExecuteNonQuery();
                        lblMessage.CssClass= "alert alert-success";
                        lblMessage.Text = "Msg 23: Data updated successfully";

                        txtItemNumber.Text = "";
                        txtCost.Text = "";
                        txtDescription.Text = "";
                    }
                }
            }
            else
            {
                lblMessage.CssClass = "alert alert-warning";
                lblMessage.Text = "Msg 23: something went wrong. Please try again";
            }
        }

The code returns 

Msg 23: Data updated successfully

But the data is not populated in the IC_Item_M table.

Regards,

Deepak