Just a small point - are you sure it was 100ft? Do you have something to compare aircraft's height with?
I just ask, 'cos it's notoriously difficult judge the the height of an aircraft from the ground. Not saying you're wrong, just wondering if you might be.
Perhaps a neat way would be to ring up the owner (not necessarily the pilot) and ask what height they were at and tell them (politely) that you and others found it disturbing.
Hope you find an amicable solution.
MB