the initial set of words that blockchain.info gave its users had nothing to do with the key pairs the wallet generated, in other words it had nothing to do with HD wallets or BIP0-39 or any other similar key derivation protocol.
it was simply an account recovery phrase and as a result in order to get your account back you can only go back to blockchain.info recovery page or try contacting their support since they are the only ones who can help you.
try this page for recovery: https://login.blockchain.com/wallet/forgot-password