Azure Service Bus client explosion

program.cs

using System;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.Azure.ServiceBus;
using Microsoft.Azure.ServiceBus.Filters;

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            var a = new Thing();
            a.Go();
            Console.WriteLine("All finished");
            Console.ReadLine();
        }
    }

    public class Thing
    {
        string connectionString = "Endpoint=sb://<sbxonstring>";
        string topicName = "topic1";
        string subscriptionName = "sub1";

        public void Go()
        {
            for (var i = 0; i < 10; i++)
            {
                var salt = new string(DateTime.UtcNow.Ticks.ToString().ToList().Skip(13).ToArray());
                foreach (var ruleName in new[] { $"OtherRule-{salt}", $"SomeRule-{salt}" })
                {
                    Console.WriteLine($"===== {ruleName} =====");
                    RemoveRule(ruleName).Wait();
                    AddRule(ruleName).Wait();
                }
            }
        }

        public async Task RemoveRule(string ruleName)
        {
            Console.ForegroundColor = ConsoleColor.White;
            var client = new SubscriptionClient(connectionString, topicName, subscriptionName, ReceiveMode.PeekLock, new NoRetry());

            Console.WriteLine($"Attempting to remove rule named {ruleName}...");

            Console.ForegroundColor = ConsoleColor.Yellow;
            try
            {
                await client.RemoveRuleAsync(ruleName);
                Console.WriteLine($"Removed existing rule named {ruleName}, pausing...");
            }
            catch (Exception ex)
            {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine($"No rule named {ruleName} exists, this should kill the client...");
                //Console.WriteLine($"{ex.Message}");
            }
            Console.ForegroundColor = ConsoleColor.DarkRed;
            Console.WriteLine("Closing client and waiting 1 seconds...");
            await client.CloseAsync();
        }

        public async Task AddRule(string ruleName)
        {
            Console.WriteLine($"Attempting to add rule named {ruleName}...");
            var client = new SubscriptionClient(connectionString, topicName, subscriptionName, ReceiveMode.PeekLock, new NoRetry());
            try
            {
                await client.AddRuleAsync(ruleName, new TrueFilter());
                Console.ForegroundColor = ConsoleColor.Green;
                Console.WriteLine($"Successfully added rule named {ruleName}");
                Console.ForegroundColor = ConsoleColor.White;
            }
            catch (Exception e)
            {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine(e.Message);
                Console.ForegroundColor = ConsoleColor.White;
            }
            finally
            {
                await client.CloseAsync();
            }
        }
    }
}