utang not payed. she's in abroad (TnT). i don't hold any documents for assurance.

may utang sya sa akin, and i don't hold any documents for any assurance coz i trusted her coz she's my friend. so meaning verbal long po. now she's in abroad and she's staying there illegally. i visit her family here in their house pero the guard didn't allow me to get in, they said hindi daw nila ako kilala... which is very much lie. and po kaya pwede kong gawin? i want to sue her. i guess and pwede ko po maging evidence about dun sa utang nya is ung clinic na pinuntahan nmin, i mean my records sya dun about sa operation nya. in short po, inutang nya sa akin ung pinag gawa nyang operation and the whole staff sa clinic knows that i was the one paying for her operation even the doctor. i need help po, what should i do. many thanks.