Charge from "Gain Surge" on credit card -- is it legitimate? (opens in new tab)

I received notification from my credit card company of a $46.42 charge to GAINSURGE but I have no recollection of this charge. Gain Surge wants a ton of personal info (name, phone number, credit card number, etc) to tell us who made the charge so we can decide if it is real. How do I decide if this is a valid charge?