Get Access token from Spotify api - spotify

Question

I'm trying to get a access token from this endpoint using asp.net: https://accounts.spotify.com/api/token
The token i get back has Status = WaitingForActivation, Method = "{null}", Result = "{Not yet computed}".
When creating my app over att Spotify Developer i stated my Redirect Uri as http://localhost:59486/ which is my Project Url.
What am i doing wrong?
I have borrowed this method from https://hendrikbulens.wordpress.com/2015/01/07/c-and-the-spotify-web-api-part-i/
private async Task<string> GetAccessToken()
{
SpotifyToken token = new SpotifyToken();
string postString = string.Format("grant_type=client_credentials");
byte[] byteArray = Encoding.UTF8.GetBytes(postString);
string url = "https://accounts.spotify.com/api/token";
WebRequest request = WebRequest.Create(url);
request.Method = "POST";
request.Headers.Add("Authorization", "Basic YjlkZj****************************************jQ2YjM3MjE5MDE=");
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = byteArray.Length;
using (Stream dataStream = request.GetRequestStream())
{
dataStream.Write(byteArray, 0, byteArray.Length);
using (WebResponse response = await request.GetResponseAsync())
{
using (Stream responseStream = response.GetResponseStream())
{
using (StreamReader reader = new StreamReader(responseStream))
{
string responseFromServer = reader.ReadToEnd();
token = JsonConvert.DeserializeObject<SpotifyToken>(responseFromServer);
}
}
}
}
return token.access_token;
}
EDIT:
This is my Http request:
spotify.com/api/token HTTP/1.1
Authorization: Basic Yjlk....................5MDE=
Content-Type: application/x-www-form-urlencoded
Host: accounts.spotify.com
Content-Length: 29
Expect: 100-continue
Connection: Keep-Alive
grant_type=client_credentials