I'd suggest to never fly the batteries down or below 30%. I also suggest to ignore the 20 cycle 8% (DJI) rule. I was told by heli pilots that dropping down to 8% will kill the battery. What DJI want you to do with the 20 cycle rule is to "recalibrate" the battery so the meter will reflect the battery usage. I would rather my battery meter to be slightly out whack then my battery going puffy and randomly auto landing.
And finally, I think you should look at purchasing batteries from a battery manufacturer (limefeul/venom offer 12mths). I used to be a DJI battery advocate, but after 4/5 of failing/puffying up on me at average 30 fuming cycles!!!..
If I were you and if you want to get justice, purchase a battery from a dealer as they don't record the serial. Use the new receipt and send back your puffy battery with the new receipt. I don't think this is a rort as DJI is rorting you, promising 300 cycles and giving you a 90 day warranty for a $150 battery. Pathetic!!! At $150 a pop, its about $5 a flight which is about $20 an hour if you get 15m airtime per a flight.
And don't dispose the battery. Buy an ammo canister and store them. Some one on this forum will come up with a simple hack for the batteries.