I have the 20 Word pass phrase but blockchain is asking a 12 word pass phrase. I created wallet back in 2013-14.
After searching Google for a while I got this link
https://blockchain.info/wallet/forgot-password where I can enter my pass phrase and blockchain showed my identifier and password. The password and identifier are same as I know . But I'm still unable to login.
I had same issue with them, they are really shit. My information was 100% correct, also confirmed email but again I was redirected back to blockchain. Fix of issue for me was creating new blockchain account and after rhat everything is 100% ok but I don't trust them my funds, well not high amount.
Try to contact them or if you had small amount of btc, better to hang on that situation and learn on lesson.