Once connected to WiFi everthing works fine...
After trying various fixes, ROMS, asking questions, and hours spent researcing i have found a fix. The problem lies not with the phone but the Network Provider, I use Vodafone AU on my factory unlocked but Telstra delivered I9305 GT, Since Vodafone has not yet released this version they have not set up their proxy for the Google Play store. If you are facing issues when downloading from the Play Store, try this:
Settings - Wireless and networks - More settings - Mobile networks - Access Point Name \ (name of operator apn) \
DELETE: PROXY and PORT configuration !!! (leave the MMS Proxy and MMS Port alone)