AT&T phone cables to adjacent property running across my property and tangled in my landscaping

The phone cable to the adjacent property was installed from a point along our rear property line instead of from a point along the adjacent property line. We need to have this cable relocated so that it does not run across our property where it is tangled in our landscaping. We are in an older neighborhood with above ground utility cables that run along the rear property lines of every lot on our street. Please advise which department would handle this. Thank you. 

There was no category or topic that seemed to apply to this. My apologies if my choices are incorrect.