As I mentioned earlier, the response doesn't look correct JSON.
I tried to convert it to XML using:
http://www.utilities-online.info/xmltojson/ but it failed.
It converts to XML correctly if I change the response text to:
{ "$type": "Cloud.Messages.DeviceMessages.GetCCResponseDeviceMessage, DeviceMessages","Cards": {"$type": "System.Collections.Generic.List`1[[Cloud.Messages.DeviceMessages.Card, DeviceMessages]], mscorlib","$values": [] },"Status": 0}
So, I think the service should be fixed to return the correct JSON (if possible), otherwise you can write a Groovy script to parse the response into valid JSON or XML.
Best Regards,
Prakash
SmartBear Sweden