Are smok ecigs safe?

So, I currently have a eleaf Istick power and am looking to get a new mod. I really want a pink TPriv by smok or a mag. (However, I can't find a mag kit and don't want to have to buy everything separately, plus I can't decide which one I'd want anyways) My friend bought a smok V something online and when she got it the vape wouldn't turn on until it finally did and the button got jammed and the coil/tank caught FIRE. I'm not sure if it's the brand or just because she bought it online but I really don't want that to happen to me. Do you think I'd be fine if I buy in shop?