Personal Loan worth 15k need advise

Hi Good day to all the members here in the forum. I would just like to ask for an advice regarding my predicament. First off I borrowed a loan from a from my wife's friend and my previous co-worker worth 15k and I haven't had the chance to pay it till now w/c is running 3 months now regrettably as of right now he's threatening my whole family that he will file a law suite against me for not paying and posting on his wall sharing with everyone that I am a criminal and a lot of degrading things against me. We already messaged him and texted him that we still need time before we could pay the debt but he still posting ruining my credibility and such. I'm just worried that I would be charge of a crime of estafa since I have signed an agreement that I would pay it on a certain date but I haven't. Would I be liable or would I get arrested for a mere 15k debt? I hope you would be able to share your thoughts or would it be possible for a case to push through here in the philippines? Thank you