If you have been charged twice for a TIDAL subscription, it could be the result of two active TIDAL account.
Please check to see if the date of the charges. If the charges are on different dates, then this is most likely due to having second active subscription.
You can contact us below via the Submit a Request link. Please provide us with any email address that you may have used to register with TIDAL. This will help expedite the process in getting your accounts and billing straightened out.