Example of un-testable class

ReportGenerator.cs

using System.Text;
using System;

namespace BigLegacyApplication
{
    internal class ReportGenerator
    {
        public ReportGenerator()
        {
        }

        internal string GetUserReport(int userId)
        {
            var userService = new UserService();
            var user = userService.GetUser(userId);

            var resultsService = new ResultsService();
            var results = resultsService.GetUserResults(userId);

            var sb = new StringBuilder();
            sb.AppendLine(string.Format("{0} {1}", user.Firstname, user.Surname));
            sb.AppendLine(string.Join(",", results));
            sb.AppendLine(string.Format("Date: {0}", DateTime.Now.ToString()));
            return sb.ToString();
        }
    }
}