I know someone who have the same problem as you. After lots of texting & chats which most of all they retained as evidence , the landlord never runs out excuses..until my friend have enough and threatened to take them to court.. you must have the papers to show your deposit ..would you believe ..the next day , they received the money..
got oCASE--you juts need 20 deposit.....then they set up a mediator...

Most often Chinese doesnt want to go that far ..
Good Luck

Cheers
palinsingapore