doo GmbH is running the platform doo.net and, as a service provider, takes over online-bookings, billing and payment handling, email campaigns for organizers of seminars, courses, advanced education, workshops or similar events.
The credit card was probably charged due to an online registration for one of these events. After your booking, a confirmation e-mail with the corresponding invoice was sent to the e-mail address provided during the booking process.
If you still cannot allocate the credit card charge from doo.net, you can contact our doo customer service with the following information:
- Booking number (starts with TX-XXXXX-XXXX)
- Date of transaction
- Credit card details (credit card holder, last 4 digits of the credit card number, expiration date)