Well first and foremost, Venom stands behind their products 100%. They will do whatever it takes to make your problem right. As far as quality of packs, I still have one green 5000 20c pack that runs just as good as some of my newer 5600 60c packs. It also show are 2 milli ohms of resistance. That is very low, & allows for the most current to flow. Resistance testing is only a gauge for your own benefit. It's like old school NiMh matching. You can't go by others rating simply due to the fact that they use a different machine, and or ways.
I now have in my race bag some 4500 100c, 6000 100c, & 5800 100c. Every pack is treated the same. They are charged @ 10A, used for the race, cool off, put into storage mode @5A. This is sort of conditioning your batt5. I promise you will see positive results. BTW, I use my 4500 100c packs in my 1/8 E buggy and run for at least 11 minutes full boogy. They don't puff, swell, or anything. Maybe your demand is too high for the C ratings of the pack. If the demand is too high, it strains and over works the batteries, causing serious issues such as your experiencing.
What charger are you using, charge rate, store rate, & vehicle. Then what pack are you using per vehicle.
Let me know if I can help.