The April 2012 WT study article has some of the most strongly worded statements about contact with disfellowshipped family members.
Page 12, paragraph 17: -
17 Consider just one example of the
good that can come when a family loyally
upholds Jehovah’s decree not to associate
with disfellowshipped relatives. A
young man had been disfellowshipped
for over ten years, during which time his
father, mother, and four brothers “quit
mixing in company” with him. At times,
he tried to involve himself in their activities,
but to their credit, each member
of the family was steadfast in not
having any contact with him. After he
was reinstated, he said that he always
missed the association with his family,
especially at night when he was alone.
But, he admitted, had the family associated
with him even a little, that small
dose would have satisfied him. However,
because he did not receive even
the slightest communication from any
of his family, the burning desire to be
with them became one motivating factor
in his restoring his relationship with
Jehovah. Think of that if you are ever
tempted to violate God’s command not
to associate with your disfellowshipped
relatives.