Membership automatically charged without consent (Barcelona)

I think I've already read a simiilar complaint about this here. After being a basic memeber for a year I thought I´d try being an albatross so that I would oblige myself to socialize more at Internations. I paid the 3-month trial by credit card. Now they have automatically charged me the next 3 months through my card . I do not think I have signed any contract or given permission for Internations to charge me automatically and periodically. I really resent it and it turns me off totally. I am gonna check the legality of this, because I do not think is it proper and may even be considered illicit. Can anyone give me an Internations admin address please? Thank you