I was employed by an old college friend for building an App. I was paid an advance of 25 percent of the total amount agreed as an advance to start working. Later, I went to his office for a few days to meet up his boss, talked to him but after some days unexpectedly we got into a huge fight and now he doesn't want me to work on it anymore, I also left on same terms. Now he is demanding the money back or incase I don't want to return the money he is asking me to sign the agreement for his audit.
This is not making any sense to me and I don't want to pay him back , as I did give my time to the project and I didn't have any intention to leave the project. I haven't started working yet , I agree but he also agreed that it was his failure to hire me. In that case why is he expecting me to sign or refund. I feel like if I sign I'll be in more trouble.
He started harassing my friends also as I'm not responding, sending them messages on social media platforms. I seek advice as to how to handle this.
P.S. : This is my first time here , if this is not the place to post this kind of question, please kindly direct me to which community.TIA.