Why must your gf respond to him?
He probably in state of denial; thinking that he still have hopes
with her.
And because she responded to him, be it negative/positive, he took
it as a respond, which means he probably have a slight chance to
get back to her.
This guy is probably a little extreme: I have three unorthodox
levels, increasing in intensity.
I) Let her have one final talk with him. Let them settle this
themselves. She has to let him know that they are OVER and it's
IMPOSSIBLE for them to be together because she NO LONGER loves him.
There will probably be strong resistance and conflicts, therefore
it is advisable to meet in the day instead of night. She make her
ideas known to him, and tells him that if she feels harassed again,
byebye - level two is activated. (This is positive)
II) Complete ignore. No respond of ANY kind, even if he threaten
suicide. He place his gift, it is left at where it is. Tell all
your family and whoever, that nobody is suppose to touch that
thingy and instruct to leave it where it is. This should settle it,
if not... (This is neutral)
III) Extreme. Maintain level two, just that she become extreme and
seek ways to destroy that ego of his. Smash his present outside the
house and leave it that way. Still avoid contact and if
circumstances is such that she has to speak, employ strong body and
verbal language to fight her way through. (This is negative)
You should also give her some time to get through this mini drama.
Don't pressure her to solve everything; the issue here is WORK
TOGETHER to end this drama. She is probably trying to do her own
method, but if it doesn't work, it is time to come together and
find some solution mutually. 
Cheers
