C# Online Compiler | .NET Fiddle

using System;
using System.Collections.Generic;
using Newtonsoft.Json;

public class Program
{
	public static void Main()
	{
		string JsonResults =
                "{\"records\":[{\"PK\":\"1_1_8\",\"ID\":\"8\",\"DeviceID\":\"1\",\"RootID\":\"1\",\"CustName\":\"test1\",\"CustSurname\":\"test2\",\"Address\":\"Nisou 1\",\"City\":\"\",\"ZipCode\":\"\",\"PhoneNumber\":\"45646\",\"HomePhoneNumber\":\"\",\"Email\":\"\",\"Notes\":\"\",\"Owner\":\"1\",\"LanguageID\":\"1\",\"LanguagePK\":\"\",\"DeletedFlag\":\"false\",\"created\":\"2017-10-25 10:15:00\",\"modified\":\"2017-10-25 09:35:43\"},{\"PK\":\"1_1_33\",\"ID\":\"33\",\"DeviceID\":\"1\",\"RootID\":\"1\",\"CustName\":\"\",\"CustSurname\":\"\",\"Address\":\"\",\"City\":\"\",\"ZipCode\":\"\",\"PhoneNumber\":\"\",\"HomePhoneNumber\":\"\",\"Email\":\"\",\"Notes\":\"\",\"Owner\":null,\"LanguageID\":\"0\",\"LanguagePK\":\"\",\"DeletedFlag\":\"true\",\"created\":\"2017-10-25 10:13:54\",\"modified\":\"2017-10-25 10:13:54\"},{\"PK\":\"1_1_16\",\"ID\":\"16\",\"DeviceID\":\"1\",\"RootID\":\"1\",\"CustName\":\"Theodosis\",\"CustSurname\":\"\",\"Address\":\"Dali\",\"City\":\"Nicosia\",\"ZipCode\":\"2540\",\"PhoneNumber\":\"45645\",\"HomePhoneNumber\":\"99123456\",\"Email\":\"theodosis@gmail.com\",\"Notes\":\"\",\"Owner\":\"\",\"LanguageID\":\"1\",\"LanguagePK\":\"\",\"DeletedFlag\":\"false\",\"created\":\"2017-10-25 09:36:22\",\"modified\":\"2017-10-25 09:36:22\"}]}";
		var observation = JsonConvert.DeserializeObject<DataContainer>(JsonResults);
		
		foreach(Customer customer in observation.records)
			Console.WriteLine(customer.PK);
	}
	
	public class DataContainer
	{
		public List<Customer> records { get; set; }
	}

	public class Customer
	{
		public string PK
		{
			get;
			set;
		}

		public int DeviceID
		{
			get;
			set;
		}

		public int ID
		{
			get;
			set;
		}

		public string RootID
		{
			get;
			set;
		}

		public string CustName
		{
			get;
			set;
		}

		public string CustSurname
		{
			get;
			set;
		}

		public string Address
		{
			get;
			set;
		}

		public string City
		{
			get;
			set;
		}

		public string ZipCode
		{
			get;
			set;
		}

		public string PhoneNumber
		{
			get;
			set;
		}

		public string HomePhoneNumber
		{
			get;
			set;
		}

		public string Email
		{
			get;
			set;
		}

		public string Notes
		{
			get;
			set;
		}

		public int? Owner
		{
			get;
			set;
		}

		public int LanguageID
		{
			get;
			set;
		}

		public string LanguagePK
		{
			get;
			set;
		}

		public bool DeletedFlag
		{
			get;
			set;
		}

		public DateTime created
		{
			get;
			set;
		}

		public DateTime modified
		{
			get;
			set;
		}
	}
}

 
using System;
using System.Collections.Generic;
using Newtonsoft.Json;
​
public class Program
{
    public static void Main()
    {
        string JsonResults =
                "{\"records\":[{\"PK\":\"1_1_8\",\"ID\":\"8\",\"DeviceID\":\"1\",\"RootID\":\"1\",\"CustName\":\"test1\",\"CustSurname\":\"test2\",\"Address\":\"Nisou 1\",\"City\":\"\",\"ZipCode\":\"\",\"PhoneNumber\":\"45646\",\"HomePhoneNumber\":\"\",\"Email\":\"\",\"Notes\":\"\",\"Owner\":\"1\",\"LanguageID\":\"1\",\"LanguagePK\":\"\",\"DeletedFlag\":\"false\",\"created\":\"2017-10-25 10:15:00\",\"modified\":\"2017-10-25 09:35:43\"},{\"PK\":\"1_1_33\",\"ID\":\"33\",\"DeviceID\":\"1\",\"RootID\":\"1\",\"CustName\":\"\",\"CustSurname\":\"\",\"Address\":\"\",\"City\":\"\",\"ZipCode\":\"\",\"PhoneNumber\":\"\",\"HomePhoneNumber\":\"\",\"Email\":\"\",\"Notes\":\"\",\"Owner\":null,\"LanguageID\":\"0\",\"LanguagePK\":\"\",\"DeletedFlag\":\"true\",\"created\":\"2017-10-25 10:13:54\",\"modified\":\"2017-10-25 10:13:54\"},{\"PK\":\"1_1_16\",\"ID\":\"16\",\"DeviceID\":\"1\",\"RootID\":\"1\",\"CustName\":\"Theodosis\",\"CustSurname\":\"\",\"Address\":\"Dali\",\"City\":\"Nicosia\",\"ZipCode\":\"2540\",\"PhoneNumber\":\"45645\",\"HomePhoneNumber\":\"99123456\",\"Email\":\"theodosis@gmail.com\",\"Notes\":\"\",\"Owner\":\"\",\"LanguageID\":\"1\",\"LanguagePK\":\"\",\"DeletedFlag\":\"false\",\"created\":\"2017-10-25 09:36:22\",\"modified\":\"2017-10-25 09:36:22\"}]}";
        var observation = JsonConvert.DeserializeObject<DataContainer>(JsonResults);
        
        foreach(Customer customer in observation.records)
            Console.WriteLine(customer.PK);
    }
    
    public class DataContainer
    {
        public List<Customer> records { get; set; }
    }
​
    public class Customer
    {
        public string PK