Hi,
I daven in a relatively small minyan on Shabbos, there are anywhere between 15-20 people on a given week.
There are no regular Kohanim that daven with us, and there are two regular Levi'im.
The "sheeta" of the gabbim is never to call up a Levi for rishon in the spot of a Kohen. While the 15-20 people get an Aliyah at least twice a month, the two Levi'im only get an Alyiah in the rare event that a Kohen joins the minyan, which can take up to several months at times.
I was wondering if this is a proper practice to davka not call up Levi'im?
Answer:
A levi may be called for Rishon in an Ashkenazi minyan. This is the ruling of the Rama. In addition he may be called for maftir. One of these options should certainly be used to fairly distribute the aliyos among the mispallelim.
Sources:
Rama O:C 135:6, Mishna Brura ibid. s"k 24.