How to file a complaint

Xfinity has been trying to run a new outside wire to my house, since our internet signal is much slower than what it is supposed to be (and what I pay for). They always show up w/o advanced notice despite I asked for appointment to be at home. First, they ran a wire digging up my neighbor's lawn (w/o permission) and my lawn - running the wire ~twice as long as it is currently. Then, I managed to meet them and explain where they can possibly run a new one. They tried and then left after ~6 hrs stating that they cannot go through the concrete sidewalk. then last week while we were on vacation (again, no advanced notice) they came again - put down some wire  - while doing this they cut the irrigation system, so when we came home I found water gushing from our garden to the street (we are on a hill). THey also dug ip plants and scrambled the rocks supporting the hill - and again they did not succeed with running a few wire. so, I have damage to our garden and still no improvement in speed.