XML Parsing Error response data in ajax Phonegap

I use javascript language call web service to web server nusoap 0.7.3 under PHP language, why response data json encode not work. I checked output special character data.

Page Search Stores is shown.
Send a request to web server.
URL: http://ift.tt/1ujcKUY
Request HTTP method: POST
Form data: {"refresh":1,"FilterZipCode":"store abc"}
Web service type: soap1.1
Request data type: text/xml
Response data type: xml
Namespace: http://tempuri.org/
Method name: ExcuteStore
With Credential: false

Ajax header.

Response header:

Cache-Control   max-age=600, private, must-revalidate
Connection  close
Content-Encoding    gzip
Content-Length  582
Content-Type    text/xml; charset=UTF-8
Date    Mon, 19 Jan 2015 20:11:06 GMT
Expires Mon, 19 Jan 2015 20:11:07 GMT
Server  Apache
Vary    Accept-Encoding
X-SOAP-Server   NuSOAP/0.7.3 (1.114)

Request header:

Accept  application/xml, text/xml, */*; q=0.01
Accept-Encoding gzip, deflate
Accept-Language en-US,en;q=0.5
Authorization   Basic 
Content-Length  323
Content-Type    text/xml; charset=UTF-8
Cookie  _ga=GA1.2.1851659214.1419828593; 
Host    posabc.com
Referer http://ift.tt/1B8oIjx abc
SOAPAction  http://ift.tt/1ujcKV0
User-Agent  Mozilla/5.0 (Windows NT 6.1; WOW64; rv:35.0) Gecko/20100101 Firefox/35.0
X-Requested-With    XMLHttpRequest

Response data Json encode empty, but i check in response data output special character.

Response data:

��������Tko�0�+W�4�DNN2� �I@�de��X-Z�3ۼ4����� �j�HIn�sν��q�j�HE��3�Аai@������}�:��]5��p��wA��H�R�FEpohOR��i��Y��Pӂũ����L�M-�n���Z����كm�B��~o������TȘN�v^��"ս�lj'���l۬S���f��d,'�D����j��.�"]��^U霓���E �)ih��@H�2j�~~��d��͚��K�do�΂�)l/HR�V�p�D��.!{�r��뷓�n�GVNm�{%�����D�ٮ�c䔎tc�̅�4�9�p6�D�|%�0+�a\B�_ro+�rZIH��h����8eP]�N6�\y������X�:'��]��\�C��e�Nb���JTc���M��1�߭^{�q=6��mW�ŭQ��0v�p2M�[��5/Ό�i�lK�Bv P�W�I��qN�@{�T2���C�C����*�I�g����tl�����燺y�7�����ɝ������ڨ�s��

XML Parsing Error below:

XML Parsing Error: not well-formed Location: moz-nullprincipal:   {9b4cd157-497f-4cdb-b8da-691bf98958ad} Line Number 1, Column 1:

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Can help to solve that.

Thanks Advanced!