BT blocked access to an email account I’ve had for more than 20 years

I can’t access my email or contacts and worry that people sending me emails might think I am ignoring themHaving run my email account for more than 20 years, BT decided three months ago to block access to it.I can’t access my old emails and contacts list, but worst of all the account still accepts new mail. This means my contacts will assume I am ignoring their messages. I have written to BT twice and got nowhere. When I repeatedly phoned to ask how soon I could close the account I w