Hi, during this recent bad weather my right hand windscreen wiper froze to the windscreen of my 2013 Isuzu D Max and when I came to switch it on the the left hand one swiped but the right did not. The ridged thread bolt (sorry I don`t know the correct term) has worn and now just rotates within the hole of the windscreen wiper arm itself as its threaded. Does anyone know if this threaded/ridged bolt can be replaced or is it the whole assembly. I have a feeling that if I go to an Isuzu dealer they will want to sell me the most expensive option. Any help would be gratefully appreciated