Account seems to be downgraded

On saturday 06/29, everything was working perfectly, I could connect to the launcher, play on my server, ... But since sunday 06/30, I am only able to connect as if I never payed the game and I can only launch demo mode. Plus the launcher identifies me now as "Player", I guess it should be a default nametag

My login in game is BennyPiFlex, it comes from an old account that was migrated last year. I remember I first played and payed nearly 10 years ago so I don't think I can retrieve the so called "Transaction ID" ...

Is there a way to retrieve my account as before ?

Is it the right place for a subject like this one ? (I don't think so but I didn't find another place )