Access Token expiry quickly or Operation timeout issue.

Hi,

I am able to get access token and able to perform some dataset operations like Add row or get dataset Id.

Problem is that after 2/3 operations/ web calls, it is throwing time operation timeout exception. 

When I check the AuthenticationResult object  - it is showing expiry time well ahead as 1 hrs. But when I run the application it very soon expires say within 2/3 api calls. 

Here is my code -

private static string GetToken()
{
string clientID = "XXX";

string redirectUri = "https://login.live.com/oauth20_desktop.srf";

string resourceUri = "https://analysis.windows.net/powerbi/api";

string authorityUri = "https://login.windows.net/XXX/oauth2/token";

AuthenticationContext authContext = new AuthenticationContext(authorityUri);
AuthenticationResult authResult = authContext.AcquireToken(resourceUri, clientID, new Uri(redirectUri));
string token = authResult.AccessToken;

Console.WriteLine(token);

return token;
}

private static void AddRows(string datasetId, string tableName)
{
string powerBIApiAddRowsUrl = String.Format("https://api.powerbi.com/v1.0/myorg/groups/{0}/datasets/{1}/tables/{2}/rows", group_id, datasetId, tableName);

HttpWebRequest request = System.Net.WebRequest.Create(powerBIApiAddRowsUrl) as System.Net.HttpWebRequest;
request.KeepAlive = true;
request.Method = "POST";
request.ContentLength = 0;
request.ContentType = "application/json";

//Add token to the request header
request.Headers.Add("Authorization", String.Format("Bearer {0}", token));

//JSON content for product row
string rowsJson = "{\"rows\":" +
"[{\"ProductID\":10,\"Name\":\"Adjustable Race\",\"Category\":\"Components\",\"IsCompete\":true,\"ManufacturedOn\":\"07/30/2014\"}," +
"{\"ProductID\":10,\"Name\":\"LL Crankarm\",\"Category\":\"Components\",\"IsCompete\":true,\"ManufacturedOn\":\"07/30/2014\"}," +
"{\"ProductID\":10,\"Name\":\"HL Mountain Frame - Silver\",\"Category\":\"Bikes\",\"IsCompete\":true,\"ManufacturedOn\":\"07/30/2014\"}]}";

//POST web request
byte[] byteArray = System.Text.Encoding.UTF8.GetBytes(rowsJson);
request.ContentLength = byteArray.Length;

//Write JSON byte[] into a Stream

using (Stream writer = request.GetRequestStream())
{
writer.Write(byteArray, 0, byteArray.Length);

try
{
var response = (HttpWebResponse)request.GetResponse();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}

Console.WriteLine("Rows Added");}
}

When I call the AddRow()  in loop say loop of 5, it throws the exception that 'System.Net.WebException: 'The operation has timed out'' for request.GetRequestStream() method after 2/3 call.

What is i am missing. 

Please help.