steps for filling estafa

good pm! yesterday I received a text message stating that they are fiscal office and some one was filed an estafa case for me. I called the number and they give another number, they said the complainant. I called that number. The girl that I have talked to said that the complainant is the lending company I have loan before. I was shocked because their office near my placed was closed 3payments before I am totally paid. One time their staff texted me and ask for my monthly amortization. I paid my monthly amortization and we had an agreement that he will go to my place to get my monthly amortization since their office was closed. But he did not come after that. I try to contact him. We dont have communication after that. Now I am surprised that they will file a case against me. Its only 3payments left before I am totally paid. When I asked for my payment they texted almost the whole amount of my loan, as if I only paid once.
Please help me understand this? If they are filling estafa case against me, is the text that I received stating that they are the fiscal office is authentic? What are steps in filling estafa?