RE: Zippiy Compacts
Unfortunately that is the risk we take with the less expensive brands/sellers of lipos. Zippy batteries cost ~1/2 or less of the 'name brands', so if 1 out of every 3 batteries is bad, you are still technically ahead.
I have had 1 return with HK and while it took some time, they did issue a refund for the item (power supply).
*Try their online chat.
Hobbypartz.com ships from USA and supposedly has good customer service regarding batteries. I weighed this all out when buying my most recent packs, and did not buy from HK for the fear of one being bad and the time/cost to replace it. Next batteries will be from F3AU.