Genius Bar damaged my iPhone...

I have an iPhone 4 16gb model with AT&T and love it. I have moved from the 3G model to the GS and finally to the 4. We have 5 iPhones on my current family plan and have been very loyal to AT&T and Apple with our service and products.

WIth all this being said, I am pretty dissapointed in what happened a few weeks ago on a visit to my local genius bar (which I will keep anonymous as they typically have been very helpful). I thought I was having some problems with my earpiece volume as my wife's iPhone 4 seemed to work a little better than mine. I tried a few things that I found in the apple forums and finally made an appointment at the Genius Bar to have them check it out for me. The phone is definitely out of warranty and I was prepared to pay to have it serviced if necessary. They did some checking and than took it into the back to "take it apart and clean it". When they came back, the earpiece volume didn't appear to be any better, but since they said they couldn't find any thing wrong with it I just accepted that I would have to keep the volume up and left. I noticed after a few days that my home button started to not work everytime I pushed it. Sometimes it would behave normally and sometimes I would have to push it a few times to get it to work. I reset the phone and tried some cleaning tips I found online, but it has been getting progressively worse. So I made another appointment at the same Genius Bar and asked them to see if maybe when the took it apart to clean it if something did not get lined up properly to cause this problem. I was told that they do fail on occasion and I needed to buy a replacement phone! No offer to have someone take it apart again and check it or even acknowledge the possibility that they could have damaged the phone. I tried to emphasize that I brought the phone in for a perceived volume issue and left with a damaged home button. No one seemed to care about that fact. I will emphasize that everyone there was pleasant, so I left a little perplexed and now am starting to actually feel pretty upset about how I was taken care of at this Genius Bar. I got my phone back from them in worse condition than when I walked in the door and the whole attitude is like, "gee, I'm sorry, guess you have to buy another one!".

Am I out of line here thinking they should take some responsibility for this? If not, are their any suggestions on how I can appraoch Apple about this problem?

I will emphasize that everyone that I have ever dealt with has been very curteous and for the most part helpful and this one experience isn't going to make me go out and buy all new Samsung Galaxy IIIS phones as we love our Apple products. I just feel that I should have at the very least got my phone back in the condition it was before they worked on it........