Students blocked?

I have two students who tried to register and they some how can't access and sign in. 

It's like their account is blocked. 

I tried to create a new account for them but it says their account already exist with the given email and username. Could you please unblock these accounts?

 I need to get them into their respective groups. 

Nicole Laryonava : [email protected]

Emma Venne : [email protected]