I have just come across this forum this has happened to me too.
I was approached by Alan O Hara Easy Tax Claims to join the EIS.
A few months later HMRC requested certificates for the scheme which I didn't have.
After months of emails , appeals I now have to pay back £3741 from which I only received £1000.
My appeal failed because HMRC are saying I played a part as I gave Alan O Hara (or a few of his alias') access to my gateway account.
I cant believe the HMRC weren't aware of this scam