Thanks for your reply. Actually, the support just replied and repeated the fact to me, but no alternatives/solutions/reason, although I went through the correct process. Review from Forum posts, the perception of applying developer account is by luck and slow response, you won't know why the process is stuck in somewhere. May I ask if I try to buy new clean apple devices, register new apple ID, but same ID card, can I apply the developer account successfully?

same case for me, long time to wait but no responses by email, for 2 fa auth, this may help https://appuals.com/this-phone-number-cannot-be-used-at-this-time-try-again-later-cannot-verify-phone-number-in-apple-id/

sorry, i suppose the previous request have not yet posted and i created duplicate post here. the admin can delete one of my post, i do hope the support here can review my case and give me the solution/alternatives