The reason why some players may see a ”random charge” on their bank account for a day when they did not actually make a booking or played at your club is due to a 6-day reservation period that Nettla can reserve an amount on a players account.
This is due to VISA, Mastercard, and AmEx rules, and means that a previously ”reserved amount” has to be charged on the 6th day after the purchase was initiated. The player will still receive a refund if they cancel their session, or if other players join their session and paid their parts.