You need to have your neuro write a letter and contest that decision. I used to have to fight to get my DHE for my migraines- the only way insurance would cover the expense was having my neurologist send a letter of medical neccesity. After all, it is cheaper for them to give you a few extra pills than have you head to the ER a couple times a month. As long as they see that they are saving money- you will be golden!
Off Topic- Have you noticed there are quite a few people on here with Migraines and UC or Crohns? I'm a crohnie myself.