Can you guys help me find the best ecig for refilling instead of buying new cartomizers/cartridges constantly. I'm using an njoy npro duo, I really enjoy it but it's too expensive to buy new carts all the time and refilling them just isn't working very well. They tend to burn the wicking and filler material a lot. So if anyone could tell me what some of the best design/model are for refilling I would greatly appreciate it. Also if anyone could tell me the best canadian supplier for which model they are proposing I would be happy to hear that as well. Thanks a bunch