Thank you for notifying us. This is HIGHLY unlikely a problem on our end. Due to the numerous transactions this person may have made we find it extremely disappointing and false that the blame has been put on us.
This is what the owner of Nicotine River responded with on the link you provided,
I genuinely appreciate your business and the kind words about us. The likely hood of it being our fault though my friend is slim to none. There is always a possibility and I honestly can't rule that out but to be honest how would someone get your credit info? We don't even know your CC info and we are the merchant. All we can see on our end is the last four digits of the card and the basic information of the card holder such as first and last and the address is being shipped too. We don't keep cards on file nor do we take cards over the phone. I saw your email to us earlier and I haven't responded yet because I am waiting to hear back from our website managers in regards to what safe guards Shopify has which is the platform we use. We have had tons and tons of fake fradulent transactions from international orders but rarely domestic. When I say fraudulent I mean random people steal card info and place orders on our own website trying to get free product. Your situation is very different and it isn't really fair to place the blame on us. I am sorry that happened to you but again I genuinely doubt it is us.