Deleting an old username and posts

Hi, I have an old account and posts that I wanted to delete. For some reason I can't log in as the account seems to have been deleted, but all the posts are still up. Im not sure if you delete inactive accounts after a certain period of time?

Could I please get the old account and posts deleted so there is no trace of it?

Also, you tweeted one of my posts, could I also get the tweet deleted?

If I could talk to someone privately via private message to sort it all out, that would be great.

Many thanks.