Twisp edge is unreliable

My boyfriend and i wanted to quit smoking and together we both bought matching black twisps, i got the solo and he got the edge. Extremely happy with my solo (and still so) it was working and tasting great, however my boyfriends experience was a bit different on the first day of using his twisp it was great but by the second day it tasted burnt and rather gross, i took it to twist in sandton and was recommended to change the atomiser head , so i did and purchased more atomiser heads... the same day the burnt taste returned , when i took it back to twisp they said there was no problem. When telling a friend about the situation it turned out the exact same happened to him and his edge and he ended up buying an Aero. I am disappointed to hear this because twisp solved his problem and he payed in the extra for his Aero, yet twisp is not helping me sort out my problem , which as much as they would like to deny is a problem. I am now left with a twisp i payed money for that is not working and an unsatisfied customer! we just want a twisp for him that works as well as the solo! This is twisps flagship device and not only mine was faulty? and its under guarantee still but no help !