Comcast lack of proper line burial; on 4th cable line in 1 year; safety hazard

Within one year, my internet line has had to be replaced 4 times.  Each time, the supposed burial crew basically throws 1/10 inch of dirt over it.  I live in south Florida, in a townhome community and the line runs over 200 feet, through common HOA property.  The line is completely exposed throughout, or barley covered by dirt in some spots.  When the lawn maintenance crews come out, the line gets cut repeatedly.  

Having this constant issue has caused numerous days with no connection.  Hence, lost work, and my high-school age kids not being able to complete assignments.  I have lost 8 days of work in 1 year because of this.

The most recent cut was 2 weeks ago.  The line was replaced and I was promised that "THIS TIME" the line would be buried properly.  It was not.  The tech assured me his supervisor would be in touch, which has not occurred.  Meanwhile, 19 emails have gone back and forth throughout the last week between myself and the "Customer Care" , Office of Tom Karinshak.  Instead of having one specialist assist me, about 10 have reached out, all with empty promises and assuring a resolution and a proper burial.

This morning I received an email from Customer Care by "Aileen G", telling me the case (ESL04535210) was closed and someone from her office claimed she spoke with me last night.  This never occurred and is 100% untrue.

What now, Comcast?