I'm getting an Error 400 bad request when I try to retrieve data from my WCF service.

Any help would be appreciated.

Here is the code I'm using:

Sencha

Code:
var xkoreModel = Ext.regModel('xkore', {
    fields: ['name', 'data']
});


var store = new Ext.data.Store({
    model: xkoreModel,
    proxy: {
        type: 'scripttag',
        url : 'http://localhost:8523/test/xkore/xkoreMobileService/GetChartData'
    }
});
store.load();
WCF Interface

Code:
[ServiceContract]
    public interface IxkoreMobileService
    {
        [WebGet(ResponseFormat = WebMessageFormat.Json)]
        [OperationContract]
        string GetChartData();


        // TODO: Add your service operations here
    }
C#

Code:
// TODO: Overload to accept multiple different chart types
        public string GetChartData()
        {
            // This will be based on the location of the device
            CLocation location = new CLocation();    


            // Send back a nice stock out chart
            return (Chart.GenerateStockOutChart(location,21)).GetFormattedChartData();
        }