Parsing XML returned from a transaction callback

I'm making a Payex transaction callback and it returns XML in this way :-

bf83f0761adf492e9c41cd8cf7b1c9602014-12-02 20:29:32
OKOKOKOK00c8d509091b7840799c2cde958b7a83be50149456020VISA500True00000001-4925-0000-0004-00000000000002000000001-4925-0000-0004-000000000000Y3DSecure49**********0004133766612/2/2014 5:01:03 PMfalsefalse

The above content seems to be XML, however, I'm unable to understand how can I parse it into XML with the correct tags. I can use SimpleXML to generate an XML, but how can I parse this?