Check the e-mail account settings on the iPhone and iCloud. In this way you will see which e-mail account contacts are being synced.
First make sure that the calendar on iCloud does not contain any duplicates, If it does not, then do not synch your calendars with both iTunes and iCloud.
Settings | iCloud | Turn Calendars to off | Replace calendar on your iPhone using iTunes.
To use Wi-Fi only, without any data/roaming charges you need to:
Switch on AIrplane mode.
Switch on Wi-Fi mode.
You will be able to use Wi-Fi without incurring any mobile network costs.
You will not be able to receive any calls or SMSs.
Making the world a better place by sharing information.