Issues inserting HTML format for fields using API for change

Currently, the GET request for a change returns the encoded html data for the Description field, however when I try to add or update html entries, via the url, I get an error for the connection resetting (via SoapUi through my application, it simply fails).

Is this a case where the entries need to be passed in JSON? If so, how is that to be done. I have escaped all the following characters, but get a failed response for "Error when parsing input XML elements - null - null" (XML Response) or "A JSONObject text must begin with '{' at character 0 of " (JSON response).

\b  Backspace (ascii code 08)
\f  Form feed (ascii code 0C)
\n  New line
\r  Carriage return
\t  Tab
\v  Vertical tab
\'  Apostrophe or single quote
\"  Double quote
\\  Backslash character

Here is a sample of the json request:

POST https://servicedesk.lenderlive.com/sdpapi/change/?OPERATION_NAME=ADD&TECHNICIAN_KEY=927A67B8-9C7F-4180-B437-067C54B61861&format=json HTTP/1.1
{
 "operation" : {
 "details" : {
 "templatename" : "General RFC",
 "workflowname" : "General RFC",
 "title" : "TEST",
 "requester" : "Mike Jackson",
 "scheduledstarttime" : "02 Jun 2016, 15:00:00",
 "scheduledendtime" : "02 Jun 2016, 16:00:00",
 "technician" : "Mike Jackson",
 "category" : "TEST",
 "subcategory" : "TEST",
 "statusname" : "Requested",
 "requestedby" : "Mike Jackson",
 "statuscomments" : "Posted by SoapUI",
 "sitename" : "TEST",
 "changemanager" : "Mike Jackson",
 "changeplanapprover" : "Mike Jackson",
 "changerequester" : "Mike Jackson",
 "changetype" : "Significant",
 "client authorization code" : "None",
 "assets" : "",
 "application(s) affected" : "TEST",
 "priority" : "Medium",
 "risk" : "Medium",
 "urgency" : "High - Core Business Service",
 "project id" : "any",
 "impact" : "High - LOB/Office/VIP Group/Public Facing",
 "servicesaffected" : "",
 "notifications" : "Everyone ",
 "division(s) affected" : "All",
 "post change validation plan" : "Test",
 "service interruption policy exception" : "N/A",
 "emergency" : "no",
 "reasonforchange" : "New services",
 "description" : "<!DOCTYPE HTML PUBLIC \"-\/\/W3C\/\/DTD XHTML 1.0 Transitional\/\/EN\" \"http:\/\/www.w3.org\/TR\/xhtml1\/DTD\/xhtml1-transitional.dtd\"><html><head><style type=\"text\/css\">a.attachlink:link { color: #0000FF }; a.attachlink:visited { color: #0000FF }; a.attachlink:hover { color: #006600 }; .indented { margin-left:50px }; .minorindent { margin-left:20px }; <\/style><title>TEST<\/title><\/head><body>Hi, This is a test <\/font><\/body><\/html>"
 }
 }
}