Agreement

Sir,
I was planning to sell a portion of my property 8-9 months back. The agreement with the supposed buyer end 3 months back and he give us some amount of money as token at first(3-4 lak), now he asking for more time for registration. And now i come to know that he do the same with many other people. Now we don't want to sell it to that person. I want to know that ,if the agreement time is over should i return the money."His tone is now change in to threat".