If Plustoken support didn't answer your messages and claims, that sounds hopeless to takes back your money even though you have all the credentials. To know that they have been shut down (unless it was only maintenance break) you can't count of them to give back what they've scam to all depositors. This is will happen to scam exchanges ( exit scam) which I worried about that is why I keep ignoring these exchanges and never give them a chance to take what I have.