I use (exclusively, as of recently) the iSmoka BCC tank, and up until a few days ago, with no issues. The other day I went to do what I had done a hundred times, and that was to open the tank to replace my juice. The thing will NOT open. We have tried everything, and it's just sealed shut, or something. I don't know if warming it up will help loosen it? or if that is safe to do? (forgive me, I'm still a vaping noob!). Any advice would be appreciated.