Are you trying to do email/zip submit for a free iphone using ppc? I suggest this is an expensive option and you should rather try CPA offers that pay you between $10-$40 for a short form fill.
I would make a list of every way that you can say "unlock iphone" but don't try and bid on unrelated keywords (like ringtones, free cell phone tips, etc.) Buying clicks for unrelated keywords will be wasted money. Also make sure you are using negative keywords (like: padlock, door, locksmith, etc.) I did not look, but I would guess that those unlock iPhone keywords are expensive. I also assume you have used the Google keyword tool - you might try and select the option to get keywords based on "Website Content" and try entering your website, and then grab the domain address from the advertiser in position one for the search term "unlock iPhone" and then enter that domain into the keyword tool and let Google scrape their site for keywords. Just remember to only use the terms that are really about unlocking iPhone. Hope it helps!