No replies to self assessment letters dated July & September 2023

Hello, hope someone from HMRC can help. I'm still waiting for replies to letters dated 15th July and 17th September 2023, both of which were sent by Royal Mail tracked post with receipt being acknowledged. There's no email address I can use to chase up, all phone numbers I use either hang up automatically or, having waited over an hour for the privilege of speaking to a human being, I get the standard 'we can't help you'. I came across this forum by fluke, but couldn't initially sign up as the Captcha and audio codes were not working. Now I'm finally signed up, I'm wondering could this forum be the only reliable way of communicating with HMRC? Unbelievable really but I appreciate that HMRC like all other public services have been slashed to the bone in the last 15 years or so. I hope someone at HMRC sees this thread and lets me know when I'll get a response to my letters, as I need my particular issue to stop hanging over my head. Thank you.

Hi,

I am sorry if you have not received a reply to your letters submitted to HMRC. As we will need to access your record to check on the progress you will need to conact HMRC.
You can contact HMRC by phone or webchat using the link below.

Contact HMRC

Thank you.