Unfortunately, people just DON'T read. You could shout it through a megaphone, post signs everywhere, tape it to the inside of their eyelids, but nothing works!!! I would reiterate to the store owner the importance of trimming the wick. And if you must be blunt and say look if you don't follow the directions, you can burn your store down, then do so! I burned one of mine at home a few weeks back and forgot to trim the wick. My boyfriend yells downstairs to me, "Hey, this wick is really high, don't you need to cut it or something." I thought he was clueless about candles, I guess not!! Guess I taught him well.