Their card reader states that there is a minimum $6 charge, but you're actually charged $18. Apparently you need to wait until the next banking day for the actual charge to go through which sounds like a scam to me. I will most definitely be checking with my bank tomorrow about this. My boyfriend had the same issue since we both went the same day and were both charged the same amount. When he called to discuss what happened he was told "Call a lawyer for your $12 then, cheap motherf*cker." and was hung up on. Way to be professionals.