Custom Web Service XML Body

I created a custom web service to accept xml from one of our lead aggregators. However, it is not deserializing the request body, and all I get in response is a Null Object Reference error. Am I missing something?

My custom web service:

namespace Terrasoft.Configuration.UsrMyLeadImportNamespace
{
    using System.Collections.Generic;
    using System.IO;
    using System.Xml;
    using System;
    using System.Runtime.Serialization;
    using System.ServiceModel;
    using System.ServiceModel.Activation;
    using System.ServiceModel.Web;
    using System.Xml.Serialization;
    using Core;
    using Core.DB;
    using Terrasoft.Web.Common;
 
    [XmlSerializerFormat]
    [ServiceContract]
    [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Required)]
    public class UsrMyLeadImport: BaseService
    {
		private SystemUserConnection _systemUserConnection;
		private SystemUserConnection SystemUserConnection
		{
			get
			{
				return _systemUserConnection ?? (_systemUserConnection = (SystemUserConnection)AppConnection.SystemUserConnection);
			}
		}
		// Service operation.
		[OperationContract]
		[WebInvoke(Method = "POST", RequestFormat = WebMessageFormat.Xml, ResponseFormat = WebMessageFormat.Xml, BodyStyle = WebMessageBodyStyle.Wrapped, UriTemplate = "new")]
		public MyResponse New(LeadInformation leadInformation)
		{
			var response = new MyResponse();
			response.ResponseStatus = "Tracking Number is => " + leadInformation.TrackingNumber;
			return response;
		}
	}
 
 
	[XmlRoot(ElementName = "LeadInformation")]
	public class LeadInformation
	{
		[XmlElement(ElementName = "TrackingNumber")]
		public int TrackingNumber { get; set; }
 
	}
 
	[DataContract(Namespace = "")]
	[Serializable]
	public class MyResponse
	{
		[DataMember]
		public string ResponseStatus { get; set; }
	}
}

Request Body:

<LeadInformation>
    <TrackingNumber>12345</TrackingNumber>
</LeadInformation>