Know the name of the collection agency, report it to Pag-IBIG, they will make an investigation for it naman. Normal ang house visit, kasi need nila ibaba ang demand letter sa inyo. Sometimes may fb message rin, but just to gather contact, di pwede na dun ang buong negotiation. Some people on CAs are really aggressive, wag mo lang paramdam na takot ka. (7 year collection agent here!)