Lipo question

Last week I bought two Flightmax lipos from HK, one is just fine the other showed 1.22v in total for a 4s pack. Two of the cells were slightly puffy, now it's completely dead and the other two cells are puffed as well, only slightly but it's there. I have registered it on HK within 24 hours after receiving it, but the cost of shipping makes hardly worth the effort to send it back even though I'm within warranty. What I mean is if there is anything I can do to save it I will not spend the money on sending it back, but if you guys deem it a lost cause.....well.