I’m blacklisted but the problem is the account is not mine but I helped a friend to open it and now she does not pay, how can I solve this?
Unfortunately you remain liable for the account. If the account is in your name, the credit providers are well within their rights to demand payment from you. Unless you have a written agreement with your friend there is not much you can do.
I would suggest that you service the account yourself to ensure that your credit profile remains intact. Sort the finances out with your friend directly. Do not wait for your friend to pay before you make a payment on the account.