Yeah I feel you. That has happened to me too. Most annoying thing is that when you have a lot of money in a big pot in cash game and you get disconnected
Do you know how much unibet puts effort to keep ther client safe? Do they have a people working on bots and other scammers? Some other pokersites have integrity teams who make sure it's safe to play.
Nobody knows what the criteria for being invited is. Maybe it's about how much you spent or lost or turned over in the client. I haven't ever got the ticket either.