In my humble opinion, VISA (Master Card, etc) are canceling the transactions because there are the differences between the personal data you entered on the payment page and the personal data they have about you. When you open an account, the bank operator fills some data about you in the bank's database. VISA (Master Card, etc) will know about you based on this data. So, phone the bank and ask them about all your personal data, then check every character you typed in the payment page if it's identical with what the bank has in their database. In my case the data was different than what I typed in on the payment page. The bank operator simplified my address. I was surprised to see discordances between my personal data from my ID and what my bank knew about me. I will try again to make the payment.

Quote from the solution offered by "the app" user: "First Solution: Place order form Apple Developer app. Use a new apple device which is not trusted device of any other apple developer account. Signin with your apple developer id, Add payment mehtod and 1st buy an app. So your credit card will be verified. Now download apple developer app and signin with apple developer id (in some countries apple developer app do not support direct transaction) so they will provide your weblink inside app. If your country do not support direct transaction from apple developer app, click on weblink and complete transaction from mobile. Thats' it. I have renewed 1 developer account and purchased 3 new developer account using this method." Short answer: brand new iPhone SE, new iCloud account, new bank card, new telephone number, installed Apple Developer app on iPhone, bought an app from Apple Store (payment was OK), bought Apple Enrollment program (the app wasn't supporting payment inside the app for Romania so I was redirected on the payment page where I made the purchase) - after one day -> transaction canceled! So, it doesn't work for me. :(