How to write CSV over and over within For-each loop in Mule 3?

Question

Im trying to write CSV within For-each loop in Mule 3.

1. Reading CSV file
2. Passing parameter to the API to get response
3. if no response, will write into another csv file. To maintain parameter value i set record variable before API calling and no matches, would write into CSV.

But CSV file not generating within For-each loop.

 <foreach collection="#[payload.names]" doc:name="For Each">
  <foreach collection="#[payload.names]" doc:name="For Each">
  <batch:set-record-variable variableName="userName" value="#[payload.Name]" doc:name="Record Variable"/>
  <http:request config-ref="HTTP_Request_Configuration" path="/users" method="GET" doc:name="Users">
  <http:request-builder>
  <http:query-param paramName="name" value="#[payload.Name]"/>
  </http:request-builder>
  </http:request>
  <choice doc:name="Choice">
  <when expression="#[payload.results.size()>0]">
  <dw:transform-message doc:name="Transform Message" >
  <dw:input-payload mimeType="application/java"/>
  <dw:set-payload><![CDATA[%dw 1.0
%output application/csv
---
[payload]]]></dw:set-payload>
   </dw:transform-message>
  <set-payload value="#[recordVars.userName]" doc:name="Set Payload"/>
  <file:outbound-endpoint responseTimeout="10000" doc:name="File" outputPattern="users.csv" path="C://output"/>
  </otherwise>
  </choice>
  </foreach>
  </foreach>