Loading XML files into VB.NET reading only first record

Have being trying to xml data with the below schema:

This xml(XSD) cannot be altered as it is coming for an external source.

Have tried both

1:      Dim xml_doc As New XmlDataDocument(ds_dsum)
        xml_doc.Load(TextBox1.Text())

2:      xmlFile = XmlReader.Create(TextBox1.Text(), New XmlReaderSettings())
        ds_dsum.ReadXml(xmlFile)

An in both cases only the first record is read. Any suggestions please...

This is the XSD format

    <?xml version="1.0" encoding="utf-8"?>
    <xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified"     xmlns:xs="http://ift.tt/tphNwY">
      <xs:element name="ENVELOPE">
        <xs:complexType>
          <xs:sequence>
            <xs:choice maxOccurs="unbounded">
              <xs:element name="DSPVCHDATE" type="xs:string" />
              <xs:element name="DSPVCHLEDACCOUNT" type="xs:string" />
              <xs:element name="DSPVCHTYPE" type="xs:string" />
              <xs:element name="DSPVCHDRAMT" type="xs:string" />
              <xs:element name="DSPVCHCRAMT" type="xs:string" />
              <xs:element name="DSPEXPLVCHNUMBER" type="xs:string" />
            </xs:choice>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
    </xs:schema>