MBP 15" Swollen Battery

I have 2011 Macbook Pro 15" and recently have found that the battery expanded and pushed out/damaged the trackpad. The MBP did not see high usage since I have a Macbook Air that I also use. I have taken it to the genius bar and they offered to fix the trackpad but they wanted to charge me full price for the battery. The have explained that this is "normal" behavior for the battery to expand and one of the store managers even mention that the battery is designed to expand. I previously owned 4 Apple laptops and none of my batteries ever expanded instead they just stopped holding charge. This is a lability and potentially could have caused a fire and someone could have gotten hurt on the sharp trackpad edges. I refused to pay for the battery since this is not normal battery behavior. Apple is forcing me to replace a faulty battery which at that point was still holding good charge. Is there any known battery recalls or any recourse that I can take with Apple? I'm currently dealing with applecare but their strategy is to just drag out the whole issue as long as possible until the customer gives up. I was planning on upgrading to new MPB but this situation is really making me rethink my decision.