False advertising on Sony Xperia Lounge for 15% off and free delivery

Hi,
I recently bought a Sony Z2 tablet and in one of the Sony apps it provided a code i could use on their website for 15% of and free delivery on accessories
I tried to use it and it didn't work which lead me to call them.
After discussing the issue with them they sent me a code which also didn't work.
I kept calling back to see what the issue was and they kept telling me that they were working on the issue.
It has been nearly a month and the promotion ends on the 30th of August and I haven't got a response back since i called them two weeks ago.
I will make a complaint to the ACCC regarding false advertising but not sure if its worth the effort should I complain? or is there another option i could take?
I want to complain under Australian Consumer Law but i just wanted to ask everyone's opinion before i go this path
Regards
P.S Images of the promotion
http://i.imgur.com/4L62nh1.jpg
http://i.imgur.com/TslrZ8g.jpg