Sounds like me! Just ordered a 5 pack of "genuine" 2.5 ohm Kanger coils in hopes of quality control. The ones that I get from my distributor, even among the same 5 count blister pack, some lasts 2-3 days, others last 2-3 weeks. To hold down costs, I'll take them apart, remove the flavor wick, rinse it with dripping hot water, allow to dry for a couple of days.
Then burn it off & place another wick on, with a drop of e-juice & reuse. Many times these will hold up longer than out of the pack, but eventually they all burn out. If my hands were more steady, I'd rebuild them, as I was told all that's needed is camper wire & the 2mm wick that I have onhand.
Oh well, hopefully these newer ones will hold up longer, I'll soon see.
Cat