Put pressure on them. The FCC is usually pretty good against power companies, if they do not fix the problem.
Start out with a nice friendly attitude and a phone call, though.
Most power companies I've dealt with are very responsive to such reports and initiate repairs rather quickly.
If the person reporting same treats them like they would like to be treated in the first place.
Save the pressure for the rare occasion when a call or two doesn't yield a satisfactory response.