my advice...go into any lawyer and get them to do you up some sort of scare letter. it may cost you a couple of hundred dollars but i am sure you will get results pretty quick. what you want to do is something like this.

contact your ex and tell him he has a certain amount of time to come to an agreement that both of you are happy with. whether thats him buying you out or selling or whatever. the house doesnt have to be sold in that time. but get some sort of agreement signed by him that states he will pay you half of what the house is worth at the time.

if he fails to agree to this. then go into a lawyer and get then to do up a letter. have the letter say that on top of the money you are owed for what the house is worth (your half). you will be claiming rent from him backdated to the day you moved out. you will also be claiming for rent that you had to pay at your new premises coz you were unable to purchase your own place due to you not getting your half of what the house is worth. also make sure they mention that he will also be hit up for the court fees and lawyer costs.

did you purchase the house together?? are you on the house title?? if you are saying no to both or either 1. you may be up for a long battle. but if you are on the title, whether you put any money in or not, then you are well and trully entitled to you half of what the house is worth.

i suggest for now tho that you get him to meet a time frame say a week. if he doesnt, then send the letter from a lawyer. i'm 100% sure once he receives the letter that he'll contact you. you should have this sorted out pretty quick.