I had phoned them,the other day and gave them the transaction number that my bank gave me
The email was definitely generic as it started 'Dear EC Club member' and contained no specifis's other than the PNR but it did note I'd already flown
The refund came into my account today

The important thing is,they will refund costs and bank charges which in my case they don't have to
If anyone that should have got a letter didn't,I'd recommend calling as in the case of going overdrawn without permission or of direct debits bouncing or anything like that,it's a handy letter to show it wasn't your fault