JQuery function stops working when trying to submit large amount of parameters

Question

Hi,
Run CF9 on Windows 2008 R2 Server.
I have a cfm page with multiple dropdowns (some are cfselect) and dynamically generated lists of checkboxes interdependent on each other. I am using JQuery to submit data to cfc functions and to display data.
It was all working fine until we added new company with large number of records. This translated into large URL query string with a lot of parameters submitted for processing. That's when we started to have problems. I noticed when trying to directly submitting URL, if the total number of characters in URL is more than 2114 I get an error status code 302 Redirect and nothing is displayed. 
I tried to play with postParametersLimit and postSizeLimit increasing to 1000.0 in neo-runtime.xml and restarting server but, this did not help.
Below is jquery function:
function populateBills(){
   var plID;
   if ($('#planenrolldate_id').val() == undefined)
    plID = $('input[name=planenrolldate_id]').val();
   else
    plID = $('#planenrolldate_id').val();
   var sID = $('#sponsor_id').val();
   var pID = $('#plan_id').val();
   var fromMonth = $('#from_month').val();
   var fromYear = $('#from_year').val();
   var toMonth = $('#to_month').val();
   var toYear = $('#to_year').val();
   $.ajax({
    type:"POST",
    url:"../components/billing/custompremstatus.cfc?method=GetBillsArr&planenrolldate_id=" + plID + "&sponsorid=" + sID + "&fM=" + fromMonth + "&fY=" + fromYear + "&tM=" + toMonth + "&tY=" + toYear,
    dataType: "json",         
    success:
     function(data){                 
      $.each(data, function(index, item) {
       addBillsCheckboxes(item.bill_id,item.bill_period);
    }, //end the error function
    error:
     function(){
      alert("An error has occurred while fetching bills");
     } //end the error function
   }); // end ajax call      
  } // end of function

Answer 1

That's exactly from the console after I submit:
fM  9
fY  2014
method  GetBillsArr
planenrolldate_id[] 564
planenrolldate_id[] 561
sponsor_id  59
tM  9
tY  2014
When I check just one planenrolldate_id then it looks like this
fM  9
fY  2014
method  GetBillsArr
planenrolldate_id[] 561
sponsor_id  59
tM  9
tY  2014
This it cfc part:
<cffunction name="GetBillsArr" access="remote" returnFormat="json" returnType="array">
        <cfargument name="sponsor_id" type="any" required="true">
        <cfargument name="planenrolldate_id" type="any" required="true">
        <cfargument name="fM" type="numeric" required="true">
        <cfargument name="fY" type="numeric" required="true">
        <cfargument name="tM" type="numeric" required="true">
        <cfargument name="tY" type="numeric" required="true">
        <cfset var result=ArrayNew(1)>
        <cfset var i = 0>
         <cfif ARGUMENTS.planenrolldate_id EQ "" OR ARGUMENTS.sponsor_id EQ "">
            <cfset LstBills = QueryNew("bill_id, bill_period", "Integer, Varchar")>
        <cfelse>
            <cfquery name="LstBills" ...>
                SELECT bill_id,
                    (Convert(varchar(10),billing_start_date,103) + ' - ' + Convert(varchar(10),billing_end_date,103)) + ' [' + Convert(varchar(6),plan_id) + ']' AS bill_period
                    FROM ...
            </cfquery>           
        </cfif>
        <cfloop query="LstBills">
            <cfset returnStruct = StructNew()>
            <cfset returnStruct["bill_id"]= bill_id>
             <cfset returnStruct["bill_period"] = bill_period>
             <cfset ArrayAppend(result,returnStruct) />
        </cfloop>
        <cfreturn result>
</cffunction>