Poeme, are you in New York State? I'm think (but am not 100% certain) that NY is the only state in the nation that requires a new prescription for every fill of ANY controlled substance. Their state law goes above the requirements set forth in the federal law: the Controlled Substances Act of 1970.
According to the CSA of 1970, drugs in Schedule IV (which include all benzos) and Schedule III (Vicodin, Tylenol with codeine, etc) can have up to 5 refills. These prescriptions expire after 6 months, unlike non-controlled drugs where a script is good for a full year and there is no legal limit on the number of refills. Prescriptions for IV & III may simply be called into the pharmacy.
Schedule II drugs -- the most heavy duty stuff that's legal, such as morphine, OxyContin, ampehtamines, etc -- that's is required to be put in writing (no phoned in prescriptions) and no refills are allowed under the CSA of 1970.
States are free to be little Nazis and impose even tighter restrictions if they wish. For example, a lot of states specify a limit on how many days supply (like 30 or 34 days) or number of pills that can be dispensed at once, even though Federal law makes absolutely no mention of those issues.
And I doubt there is anything that requires you to go in every month even in NY state. They could simply call your prescription into the pharmacy. If they want to see you every month it's because either:
1) The doc wants to make money off 12 visits a year. Or
2) The doc is obsessive compulsive and feels the need to watch you like a hawk.