What you can try is to convert your response into a JSON object in the following way
StreamReader sr = new StreamReader(newStream);
String json = sr.ReadToEnd();
dynamic jsonObj = JsonConvert.DeserializeObject(json);
And once you have the object you can access one of its attributes as follows:
// el [0] por que es un JsonArray y define la posición en cual buscar.
var numero = jsonObj[0]["numero"].ToString();
Console.WriteLine(numero);
Look, I've tried this compiler online: link
Anyway, I'll leave you the code you use to prove it:
using System;
using Newtonsoft.Json;
public class Program
{
public static void Main()
{
String json = ("[{\"id\":\"1\",\"correo\":\"[email protected]\",\"clave\":\"123456\",\"numero\":\"+1 8XX-307-7455\"}]");
dynamic jsonObj = JsonConvert.DeserializeObject(json);
Console.WriteLine(jsonObj);
var numero = jsonObj[0]["numero"].ToString();
Console.WriteLine(numero);
}
}