First, try to find out from your pharmacist why the prescription couldn't be filled.
The pharmacist may be able to give you this information and may be able to give you or recommend another drug you can use, such as a generic version.
If you disagree with the information provided by the pharmacist, the pharmacist will provide you with a notice about your right to contact your plan to find out why the drug isn't covered, and your right to request an "exception".
You can also review your plan materials or visit the plan's website for information about how to request an exception.
Once you know why your prescription can't be filled, you should contact your doctor and give her/him this information. Then, you will need to work with your drug plan and your doctor to either