My card was charged twice by Hash X Capital (hashxcapital.com) on the same day. I had to dispute it with my bank. Hash X Capital (hashxcapital.com) then froze my account and said I had a negative balance because of the chargeback. They created the problem and then punished me for it.
Pros: Educational resources|High security standards|Excellent charting
Cons: Wait times can be long during peak hours