wow thanks for all the feedbacks, i must ask my friend to read all your comments.

according to my friend, she said she has tried many methods - soft and hard, scream at him and also sweet to him but still no use. her husband still keeps deny.

what my friend observed is that her husband seems very troubled. if there is really 'nobody' or nothing, then why he does not want to doing something about it like reporting to the tel co or turn off the phone before he goes to bed.

if a normal person receives constant prank calls at night, then what would he do? definitely will do something right.

it kind of quite clear cut that he is hiding something. something really fishy.