how to update dataset n gridview each time data is loaded

i am developing a small website where users first upload excel sheet with project names, the next page i have a gridview which displays results of stored procedure Report. the report shows learners extracted from the database using the project names. the problem i have is that when i upload new projects the gridview shows the old data or is empty. i tried to truncate the table first then run the procedure but then my gridview is empty. here is the code and stored procedure. would really appreciate the help

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
bind();
}
}
public void bind(){
SqlConnection con = new SqlConnection(strConnString);
con.Open();
SqlCommand command = new SqlCommand("BenReport", con) { CommandType = System.Data.CommandType.StoredProcedure };
SqlDataAdapter sda = new SqlDataAdapter("BenReport", con);
command.Connection = con;
sda.SelectCommand = command;
DataSet ds = new DataSet();
sda.Fill(ds);
GRDBencount.DataSource = ds.Tables[0];
GRDBencount.DataBind();
con.Close();
}

stored procedure

ALTER PROCEDURE BenReport
AS
INSERT INTO [Verify_Pbank_Projects_MassT]
SELECT DISTINCT master.id,PPRS.PPR_Caption ,CAST(replace(substring(PPR_Caption,1,CHARINDEX('[',PPR_Caption)),'[','')AS DATE)AS UPLOAD_DATE,PPRS.[Upload_Date]
From PPRS
left join master
on PPRS.PPR_Caption = masters.Caption
WHERE PPR_Caption IN (SELECT DISTINCT master.Caption FROM master)
--- Report show counts for beneficiaries to be extracted and excluded
SELECT G.ParentId ,(Select Caption from Master Where ID = G.ParentId) as PPRName,
COUNT(DISTINCT G.Field_972) as BeneficiaryCnt ,
SUM(CASE WHEN ( (G.AccountNumber IS NOT NULL AND G.AccountNumber <> 0) AND NOT
((ISNULL(cast(ROUND(G.FIELD_647,0) as decimal(18,0)),0)+ISNULL(cast(ROUND(G.FIELD_649,0) as decimal(18,0)),0)+ISNULL(cast(ROUND(G.FIELD_1233,0) as decimal(18,0)),0)) * ISNULL(cast(ROUND(G.FIELD_648,2) as decimal(18,2)),0)) = 0 ) THEN 1 ELSE 0 END) as Ben_Account_Included,
SUM(CASE WHEN NOT (G.AccountNumber IS NOT NULL AND G.AccountNumber <> 0) THEN 1 ELSE 0 END) as Ben_ZeroAccount_Excluded,
SUM(CASE WHEN
((ISNULL(cast(ROUND(G.FIELD_647,0) as decimal(18,0)),0)+ISNULL(cast(ROUND(G.FIELD_649,0) as decimal(18,0)),0)+ISNULL(cast(ROUND(G.FIELD_1233,0) as decimal(18,0)),0)) * ISNULL(cast(ROUND(G.FIELD_648,2) as decimal(18,2)),0)) = 0
THEN 1 ELSE 0 END) as Ben_ZeroWages_Excluded
FROM pb_g164 G with(nolock)
INNER JOIN P_data_search with(nolock)
ON P_data_search.RecordID = cast(G.FIELD_972 as int)
INNER JOIN C_ListItems with(nolock)
ON C_ListItems.ItemID = cast(G.FIELD_645 as int)
INNER JOIN
(SELECT m2.id as PPR_Recordid,m2.Caption,
CAST(Substring(m2.Caption, 1,Charindex('[', m2.Caption)-1) as date) PPRDate
FROM dbo.Masterm with (nolock)
INNER JOIN dbo.Master m1 with (nolock) on m.ID=m1.ParentRecordID and m1.TypeID=77
INNER JOIN dbo.Master m2 with (nolock) on m1.ID=m2.ParentRecordID and m2.TypeID=82 and m2.TransactionID>1
INNER JOIN dbo.Master_Status ms on m.Status=ms.Status
INNER JOIN dbo.Master_Status msp on m2.Status=msp.Status
INNER JOIN dbo.[Verify_Pbank_Projects_MassT] vp with (nolock) on vp.PPRName = m2.Caption AND vp.PPRDate = CAST(Substring(m2.Caption, 1,Charindex('[', m2.Caption)-1) as DateTime)
WHERE m.TypeID=72
) pb
ON pb.PPR_Recordid = G.ParentId
WHERE G.isActive = 1 and G.Status = 'C'
--AND ( G.Paid = 0 OR G.Paid IS NULL)
group by G.ParentId
--END