Same thing here. Below is the email (typos and all) I sent to Tim Cook. CEOs never read these their executive complaints department handles them.
The bottom line is they won't do anything because the number of cases is not statistically significant. So they won't admit anything.



Dear Mr. Tim Cook,
I realize you will probably not read this, but I feel I need to this. You see I am not the type to complain about bad service nor do I write letters to complain to CEO's about how bad their corporate policies are. But this experience I had at your Stonebriar Mall in Frisco,TX really ticked me off.
I went there after my 3GS, which I was using to play music in my car exploded or popped earlier that day. The phone has always been handled with care by me since I bought it in 2010. The battery was charging and holding the charge perfectly well until the pop occurred.
Pictures attached.
After checking on line, actually own the Apple Forums, I saw that apparently this was not an usual event. Looked through many pictures that showed the phone popped open like a clam.I also read the frustrations other customers had experienced when they went to the Apple stores to seek help. So I figured that this was not going to be a walk in the park.
So to cut to the chase, I went to the store and while. I was waiting for the Genius Bar I had the Manager Brenda Tetu greet me and explain to me that although she was not a technical support person she could tell me that there would be a fee I would need to pay. Another employee told me she had never seen this happen. When I finally got to speak with the advisor he was polite but told me that this is normal that these batteries have like a built in feature that causes them to expand after so many charging cycles. He explained to me that Apple was willing to replace the phone with a good battery for just the cost of the battery replacement, $79.
I think what really upset me is that here is a company worth millions of dollars with millions of loyal customers like me who swear by the quality, innovation and reliability of Apple products and who are willing to "pay a premium" for this quality and then are faced with this???
I am not an electronics engineer but nobody can tell me that this battery failure is normal, predictable and a built in feature??? Are you serious?? Apple made a phone which retailed unsubsidized for about $600 to only last 3 years and promptly self-destruct? Mission Impossible style? Come on please!
What has happened here? Where is Apple's pride for the products they make? Will my iPhone 5's battery do the same? The battery is already needing recharging sometimes twice a day. And it's only one and half years old.
I am not looking for any handouts or special dispensation. I would like to see Apple do the right thing and admit that this is a battery failure and issue a recall even if it partial. Obviously, I don't know how many of these failures have been reported. Perhaps in the grand scheme of things, it is a very small number of failures, but still this does not look good.
Mr. Cook the ball is on your court.