All I have is a 17 word passphrase and I know exactly when the wallet was created. On the other hand, a cryptocurrency wallet service provider such as blockchain.info or Blockchain.com must develop rules of action in case the owner of the wallet loses access to the email from which he would have been registered. This is a fairly common everyday situation.
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I haven't received a response from support yet.
In their new wallet version, that would be the users' BIP39-compatible backup phrase that can be restored pretty much anywhere.
Yours, the old version, however do not have a choice but to rely on their support.
Your 17-word account backup phrase is just equivalent to your walletID and password.