Hey @Harso 
I’m so sorry to hear what has happened with this whole situation. I completely understand how stressful this can be. It leads to you needing to be super careful all the time because people can easily fall victim to these kinds of scams especially as there is no payment made on your account for the £2 so you don’t think anything of it.
I don’t work in fraud or customer support (anymore) but could you try doing a PIN recovery in app? I think what might have happened is we sent you a card with a new PIN (which is common in cases when we think your PIN might have been compromised) so once you activated your card you might have accidentally entered the wrong PIN a few too many times.
If you are still having issues reach out to a member of customer support and they will be able to look into what is happening on your account 
Tiny shout out to a new feature that we just launched that should help you if you ever get a call from “Monzo” again here