In fact, this data should have been processed by Blockchain.com support so that you could restore access to this wallet.

 And immediately after this you will be able to find out private key of your address and you will be able to use the address from another compatible wallet, for example Electrum.  And forget about Blockchain.com as a “bad dream”. 

When I started corresponding with their support, I had the same data that you wrote, and I also knew exactly the date of creation of my wallet. 
And as a result, everything worked out.
 I would encourage you to continue to press Blockchain.com support for an adequate response to resolve your issue. 

By the way, I corresponded with them, sending them about 7-8 of my requests, including quotes from legislation (GDPR).  And accordingly, they also answered me 7-8 times.  At some point in the correspondence, they informed me that they had forwarded the question to technical specialists.  And after that it was decided.  In the original wallet, technical specialists replaced the email address with a new one.