After reading multiple forums I tried something which worked for me :) At least they charged me and got the confirmation email for the developer program so I made progress :D
What I did were the following:
create a new AppleID;
enrol from Apple Developer App using the new ID (this option was disabled for me until now);
followed on screen instructions (take a photo of my id, insert some personal information);
finished the enrolment but did not introduce any payment information;
Topic:
Developer Tools & Services
SubTopic:
Apple Developer Program
Tags: