My MBA is experiencing crashes. Sometimes it is a kernel crash that displays "your computer restarted because of a problem". In other instances the whole system simply freezes requiring a hard power off. Here's my dilemma: I've taken it to the genius bar twice already and reported this same problem. It has not been fixed, although some other issues were (the first time they replaced a bad microphone, and the second time they replaced a speaker which they broke after the first repair). Nothing was done for the crashing issues and they recommended I upgrade to yosemite. I did that, and my computer has crashed 4 times this week, which is even worse than before. I've had over four weeks of being without a computer due to Applecare repairs on this machine. Now I feel like I'm getting blown off because my Applecare coverage expires in a few days. I have another appointment the day before my warranty expires hoping the third time will be a charm for them to fix it. Given that I only have a few days of warranty left is there any way I can escalate this issue? Would phone/chat be better than going back to the store again?