X Ignores Security Report After User Finds Stranger's Account on Their Number

I wanted to log back into an account I had previously used on the social media platform X today, after a long time away, in order to deactivate it. When I tried logging in with my phone number, I noticed that, besides my own account, there was another account linked to my phone number that I'd never seen before. I absolutely did not create this account, and I don't know who it belongs to.
Even though my phone number is being used on this unfamiliar account, I never received any verification code, email, or notification message related to it. I'm seriously concerned about this, both because of my personal data security and because of potential problems this could cause me down the road. My own account's username was @Crowndancy, but since I had deactivated it, I'm only able to notice this issue through my phone number right now, and naturally I also can't access the unknown account in question.
I reported my situation in detail to X's help center, but I haven't received any response so far. I do not accept my phone number being used without my permission, and I'm requesting that my personal data be protected.
For these reasons, I want the unknown account linked to my phone number, which definitely doesn't belong to me, to be investigated urgently, my number removed from that account immediately, and the account closed if necessary. I'm also requesting clear, written confirmation that the security of my own account and personal information has been ensured, and that I won't be held legally responsible for any actions taken, or that could be taken, through this account that isn't registered to me. I do not accept any legal responsibility that could arise from this security vulnerability during this process.
I want X.com to urgently investigate this situation, both to secure my account and to take the necessary technical and security measures to prevent similar incidents from happening again. I want to make clear that I don't accept responsibility for any actions or transactions carried out through an account opened using my phone number, or linked to my number, without my knowledge or consent, and that this responsibility belongs to X.