Worst service ever they are giving us the runaround for a whole month now

Worst service ever!! It's been over 3 months since my mother submitted her claim and they are dragging everything, they don't call to update us what's happening we are the ones who call them every now and then and they keep extending days for feedback. Over a month they have been saying there's an outstanding document which is a hospital account and we sent it several times,last week they called and said they want a motivation letter from the doctor within 8 days and if they don't receive it they are canceling the claim. Now my question is why are they only telling us now that they want a motivation letter after 3 months? Why didnt they tell us all along? Why are they only giving us 8 days. Yhoo a.a I am naar shem imagine a whole 3 months they have been dragging the claim they are the worst shem.