web services: vendor security; hidden for each service call

Techies--

I am converting a wcf client to an ssis package.  In order for any of the methods to be called at the remote vendor's site, security information is embedded (see source).  In my  old wcf client stub, I solve this when I create a new instanc of the service call by dubbing the client credentials into the session. The WSDL only shows the startdatetime, enddatetime -- but really needs the credentials too. I tried to set this up under the connection, but that didn't work. Has anyone solved for this in their travels?

        var api = new RemoteVendorService.RemoteVendorServiceClient();
            // prepare/assign return order list with an object pointer
            List<OrdersByStatus> allorders = new List<OrdersByStatus>();
            // prepare/assign channel list container for orders
            List<OrdersByStatus> ordersubset = new List<OrdersByStatus>();
            var allOrderNumbers = new List<string>();  //contains all possible orders, irrespective of status
            try
            {
                api.ClientCredentials.UserName.UserName = username;
                api.ClientCredentials.UserName.Password = password;
                
                Array allstatus = RemoteVendorService.OrderStatusEnum.GetValues(typeof(OrderStatusEnum));
                foreach (OrderStatusEnum status in allstatus)
                {
                    allOrderNumbers.AddRange(api.OrdersGetByStatus(status, startdatetime, enddatetime));
                }