So i played all the classes except barbarian during the free trial period. Now i purchased the game on Steam and i cant play with those characters that i made during the free trial. If i make a new character i can play, but even with the new character the level limit is still 25, and on the top left side of the main screen it still says Free trial. One more thing, usually it comes an invoice from steam after purchasing to your email, but i didnt receive any invoice this time, only from Paypal.
You would want to contact Steam about any purchase issues on their platform.