If you get an error message stating that payment has failed:
Check your phone, sometimes you need to enter a code that you receive by sms, or directly in your bank's application.
Change your payment e-mail address (some are not accepted by the payment process).
Use another credit card (prepaid cards don't always work, nor do Revolut cards).
Try another browser (Firefox, Safari, Chrome).
Call your bank to authorise the transaction
Alternatively, send us an e-mail or give us a call