Hello,
1) Send a written notice to him demanding the return of the deposit amount . State in the notice that you are compelled to overstay as the advance deposit is not returned. Send it via registered post/speed post.
2) Thou also have the option to make a complaint to the local police about his not returning your deposit.
3) If the above do not yield result you will need to get a legal notice issued to the landlord/house owner.