I suppose it would be helpful to share how much you were expecting to be charged so we can better help? I know there are different tiers of subscriptions based on extra retainers or access to more alternate characters on a server. I suppose the first thing would be to check to make sure the subscription option you thought you were signing up for is the same one you were paying for?

Also I am not sure if this is the case anymore but awhile ago the payment service that subscriptions used for this game had an initial charge of a dollar that would be refunded after the actual payment went through after setting up a new payment plan. Maybe check to make sure something like this isn't also happening?