I have the no7 micro, and the cartridge is suppose to be equivalent to 15 cigarettes, but I went through the first one in a day, and I'm on the second one and after a night with it, it tastes burnt and it's really hard to get good vapor from it. I only use to smoke maybe 3 - 4 real cigs a day, so there is no way I should be going through a whole cartridge in a day. Am I doing something wrong?