AT&T cross bored my sewer line

I have had a camera placed into my sewer line for back ups and there is a utility line through it. i  have had the flags placed in my yard and the ATT line runs right through the sewer line where the blockage is. I have had to jet my sewer line multiple times.  I have attempted to contact the regional maintance rep with the number i was given and have never been called back.  Is there another person or department i can contact?