How to remove commit that does not exists but it listed on web ?

So the situation is like this(web):

This is what I see on a WEB. commit 7d00(A) is seen there and was done via WEB interface - unfortunately, it does have changes from 3f3f(C) as child. Commit f513(B) has changes from C too.

Commit C and B was done via HTTPS and SSH.

There is no branch but web states branch might be (D) - but it is not,

On a console, I did perform this. I do not see 7d00 - even for a rebase.

Any idea what to do?

$git fetch origin
$git checkout origin/master
$git reset --hard origin
HEAD is now at f513.......

$git branch
* master

$git log --all --oneline
* f513 (HEAD -> master, origin/master, origin/HEAD) XXXX
* 3f3f XXXX
* 8bfe XXXX
* 5c02 XXXX
* ad8e XXXX

### did try - but no help - cannot see 7d00
$git fsck --lost-found
$git fsck --unreachable