How to sort an unbound DataGridView control in vb.net

Public Shared Function GetTickets(ByVal strMode As String) As List(Of Tickets)
        Dim TicketList As New List(Of Tickets)
        Dim connection As SqlConnection = DBConnection.GetConnection(True)
        Dim SQL As String = ""
        Const closed As Integer = 5
 
        If strMode = "Open" Then
            SQL = "SELECT tblTicketsQueue.pkTicketID, tblTicketsQueue.DateEntered, tblUsers.UserFirstName, " _
                      & "tblUsers.UserLastName, tblUsers_1.UserFirstName AS AFirstName, tblUsers_1.UserLastName AS ALastName, tblDepartment.DepartmentName, " _
                      & "tblTicketsQueue.TicketNumber, " _
                      & "tblTicketsQueue.TicketPriority, tblTicketsQueue.TicketType, tblCategory.CategoryDesc, " _
                      & "tblProductsAndServices.ProductsAndServicesDesc, tblTicketsQueue.TicketDescription, " _
                      & "tblTicketsQueue.CloseDate, tblStatus.StatusDesc, tblTicketsQueue.fkUser, tblTicketsQueue.fkCategory, " _
                      & "tblTicketsQueue.fkProduct, tblTicketsQueue.fkStatus, tblTicketsQueue.AssignedTo, tblUsers.fkDepartmentID " _
                & "FROM tblTicketsQueue INNER JOIN " _
                      & "tblStatus ON tblTicketsQueue.fkStatus = tblStatus.pkStatusID INNER JOIN " _
                      & "tblUsers ON tblTicketsQueue.fkUser = tblUsers.pkUserID INNER JOIN " _
                      & "tblCategory ON tblTicketsQueue.fkCategory = tblCategory.pkCategoryID INNER JOIN " _
                      & "tblDepartment ON tblUsers.fkDepartmentID = tblDepartment.pkDepartmentID INNER JOIN " _
                      & "tblProductsAndServices ON tblTicketsQueue.fkProduct = tblProductsAndServices.pkProductAndServices LEFT OUTER JOIN " _
                      & "tblUsers AS tblUsers_1 ON tblTicketsQueue.AssignedTo = tblUsers_1.pkUserID " _
                & "WHERE tblTicketsQueue.fkStatus NOT LIKE " & closed & " AND tblTicketsQueue.MarkForDeletion NOT LIKE 1 " _
                & "ORDER BY pkTicketID DESC"
 
        End If
        Dim selectCommand As New SqlCommand(SQL, connection)
 
        Try
            connection.Open()
            Dim reader As SqlDataReader
            reader = selectCommand.ExecuteReader()
            Dim i As Integer
            i = reader.RecordsAffected
 
            Dim Ticket As Tickets
            Do While reader.Read
                Ticket = New Tickets
                Ticket.TicketId = CLng(reader("pkTicketID"))
                Ticket.DateEntered = CDate(reader("DateEntered"))
                If Not IsDBNull(reader("CloseDate")) Then
                    Ticket.TicketAging = DateDiff(DateInterval.DayOfYear, CDate(reader("DateEntered")), CDate(reader("CloseDate")))
                Else
                    Ticket.TicketAging = DateDiff(DateInterval.DayOfYear, CDate(reader("DateEntered")), Now)
                End If
                Ticket.TicketNumber = reader("TicketNumber").ToString
                Ticket.UserFullName = reader("UserFirstName").ToString & " " & reader("UserLastName").ToString
                Ticket.AssignedToName = reader("AFirstName").ToString & " " & reader("ALastName").ToString
                Ticket.Department = reader("DepartmentName").ToString
                Ticket.Priority = reader("TicketPriority").ToString
                Ticket.TicketType = reader("TicketType").ToString
                Ticket.CategoryName = reader("CategoryDesc").ToString
                Ticket.ProductServiceName = reader("ProductsAndServicesDesc").ToString
                Ticket.StatusDesc = reader("StatusDesc").ToString
                Ticket.User = CInt(reader("fkUser"))
                Ticket.Category = CInt(reader("fkCategory"))
                Ticket.Product = CLng(reader("fkProduct"))
                Ticket.Status = CInt(reader("fkStatus"))
                Ticket.fkDepartmentID = CInt(reader("fkDepartmentID"))
                Ticket.TicketDescription = reader("TicketDescription").ToString
                If Not IsDBNull(reader("CloseDate")) Then
                    Ticket.DateClosed = CDate(reader("CloseDate"))
                End If
                If Not IsDBNull(reader("AssignedTo")) Then
                    Ticket.AssignedTo = CLng(reader("AssignedTo"))
                End If
                TicketList.Add(Ticket)
            Loop
            reader.Close()
 
        Catch ex As Exception
            Throw ex
        Finally
            connection.Close()
        End Try
        Return TicketList
    End Function

                                              

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