Hello Mohammad,
If you would like any specific posts associated with your account removed, if you could let a member of the Community Team know via TeamSpeak with a list of posts you would like removed, they will be able to remove these for you.
We are legally obligated to retain your information for a minimum of 180 days (6 months) for processing, as per the Right to Erasure under the UK Data Protection Act of 2018, hence why we are unable to remove all of your posts/threads.
You are however welcome to edit any posts of yours you'd like and leave them blank.
Thank you.