I bought my HH .357 atty and received it on Oct. 27th and used it just like the instructions stated.  It lasted me 2 days on my 3.7 volt mod.  The atty was a 1.5 ohm.  It just quit working, no pop or anything to warn me, it simply just quit firing.  I mailed it back with a short note on Oct. 31st and have not yet heard or received anything.  I e-mailed AV as well as sent a private message to Cisco.  Still haven't heard anything.  I love Cisco atties, they are the absolute best as far as I'm concerned.  I've been 
vaping close to 3 years now and believe me when I say I've tried all of them.  I don't know what else to do now.  I guess I've just out and will have to pay for another one if I want it.  I'm not the kind to quit using Cisco atties because I would only be hurting myself.  It really just seems like I could get at least a message telling me why it can't be or why they won't replace it.  I agree with the majority here by saying that it is an excellent atty.  I even ordered a standard 1.5 ohm Cisco AFTER I sent the .357 back. And as always I got excellent service.  What do I need to do that I haven't already?