The key question here is WHY the pharmacist is refusing to fill the medication you have refills on. The two main reasons in my experience that pharmacists refuse to fill medications are due to legal issues (such as early controlled substance filling) and moral issues (such as birth control). If you want to email me an exact situation, I can give better advice if the pharmacist is in the wrong here.
The moral issue is a long standing one that has received a lot of attention over the past 10 years. The situation you often hear about is a pharmacist refusing to fill legally prescribed oral contraceptives or emergency contraception. It has been tough for lawmakers to give definite rules one way or another because it is an issue of personal belief. In general, even if a pharmacist refuses to fill a legally prescribed medication, that pharmacist must ensure that patient has access to the medication elsewhere. Otherwise the pharmacist is technically abandoning that patient and causing harm when they have a legitimate need. Every state is different in terms of their rules and regulations, and it certainly is a tough issue to hash out.
The second issue is more of a defined one and it usually comes with controlled substances. It is the pharmacists legal duty to prevent the illegal use and diversion of controlled substances. If a prescription is thought to be forged, used for addiction, medically unnecessary etc... they certainly have the right to refuse the fill. They are legally protected in these matters. Also, many states legally bind pharmacists in terms of when they are allowed to refill controlled substances. In New York for example, the ultimate user cannot have more than a seven day supply on hand before the pharmacist refills a medication.
The answer again really depends on why the pharmacist is refusing to fill the prescription. Can you give a little more background information?