3 answers
Hello
At this point, we can't do anything to help you, you absolutely need to get in touch with someone from the LBC services... Only they can clarify things
Have you tried by email? > aide@leboncoin.fr ... in Subject > Problem with my Account
Have you tried providing the credit card numbers?
Maybe you didn't pass the identity checks; the phone number; did you provide your ID card at any point?
In any case, here it is,
Wishing you good luck
And let us know if your issue is resolved and what you had to do ^^
Have you followed the steps outlined in answer no. 3?
https://forums.commentcamarche.net/forum/affich-37865127-probleme-iban-leboncoin#p37865199

Through their customer support website