Rubber ice shields are common on instals to keep water from entering
and causing damage on the first several runs. Did the old roof have
them. Did you have a problem before with the old roof or in previous
years. Here it is called an ice dam, caused by an underinsulated,or
undervented warm attic or area in the attic. Are you sure ice caused it
and not something else defective. Well you have a warranty and a case
for small claims if he did not exclude Ice Dams. Get a few pros out to
find the cause and give a price. Go to court if you feel its right. And
fix the attic so it doesnt happen again. Ice shield should have
prevented it.