Pedestrian crossing time is not working, the traffic is not paused to allow pedestrians to cross.

Pedestrian crossing time is not working, the traffic is not paused to allow pedestrians to cross. I am visually impaired with a guide-dog and rely on every crossing to get across the very busy A5. the same problem was apparent last week, but i'm not sure if it was fixed or it corrected it's self, the problem has existed for approximately 4 days. Many thanks