Contact the attorneys handling the suit.
But unless you have something in writing from Apple that guarantees no bugs, their expert witnesses will make that suit look like confetti - ALL software over 10 lines long has bugs. It's a known fact in the industry, and it's accepted. No court will ever hold that the fact that a human being isn't perfect is actionable. Apple will probably settle for a little less than it will take them to fight, the attorneys will get rich and each person in the suit will probably get a 25 cents off coupon for Apple products, good for 6 months.
If you're talking about iMessage not being compatible with SMS, it was never intended to be, so it's not actionable - it works as intended. Maybe not as you intend it to work, but as Apple intended it to work.