Hi,
Welcome to the forum
Ask the host to email
certificates@nominet.org.uk to get a transfer form, get them to fill out the first bits and forward to you, you then fill out the last bits and forward to Nominet. Then the name will be in your name.
There is a £35.25 fee to Nominet, but I would have thought if its a cock up on their part they would be happy to cover it.
As for if it is genuine... it could be or it could not be. .org.uk and .co.uk have the same manner of registrations so its possible I suppose it was a cock up.
If they do not play ball you could either take legal action or attempt to DRS the name depending on circumstances.
Cheers,
Rob.