Evidence is very important in criminal prosecution. Oral testimony will not prove guilt beyond reasonable doubt, the quantum of evidence required to convict an accused in a criminal prosecution.

The rejoinder of qatarisun is well taken, your respondent can easily deny having received money from you or simply say that the money is simple loan, and you have no case for estafa.

The essential element of estafa is "trust" and "exchange of goods or money". Prove this both and you have a case for estafa.