Issue reading XML using select single node

I'm trying to read in some xml but I keep getting an exception when using select single node. Can someone point out where I'm going wrong please?

XmlDocument xdoc = new XmlDocument();
xdoc.LoadXml(faultKciLog.ListOfTCDNumber);
var test = xdoc.SelectSingleNode("TemporaryCallDiversion/telephoneNumberBeingDiverted").InnerText;

<?xml version="1.0" encoding="utf-16"?>
<TemporaryCallDiversion xmlns:xsi="http://ift.tt/ra1lAU" xmlns:xsd="http://ift.tt/tphNwY">
    <action xsi:nil="true" xmlns="http://ift.tt/17xiQX0" />
    <createdAt xmlns="http://ift.tt/17xiQX0">2015-02-23T13:41:35Z</createdAt>
    <mainTelephoneNumber xsi:nil="true" xmlns="http://ift.tt/17xiQX0" />
    <tcdRemoved xmlns="http://ift.tt/17xiQX0">false</tcdRemoved>
    <tcdStatus xmlns="http://ift.tt/17xiQX0">APPLIED</tcdStatus>
    <telephoneNumberBeingDiverted xmlns="http://ift.tt/17xiQX0">01942261360</telephoneNumberBeingDiverted>
    <tempCallDivertIndirectAccessCode xsi:nil="true" xmlns="http://ift.tt/17xiQX0" />
    <tempCallDivertTelephoneNumber xmlns="http://ift.tt/17xiQX0">02222222222</tempCallDivertTelephoneNumber>
</TemporaryCallDiversion>