you are not locked out of content by bungie changing the level back to 300 you can still play the content the leviathan raid prestige was not part of the Osiris dlc bungie did promise they would work on the engame but they havent said how exactly yet im not supporting bungie they need to fix this -blam!- up of a game but you should ask still ask for a refund because they sold the game completely unfinished and broken but saying you want a refund because they are locking you out of content is not true as they are not locking you out of content if you bought the dlc they only locked those that didnt buy the dlc out of content they already purchased because it was impossible for those to play said content