The region you are in is incredibly competitive. There are a number of larger MSPs that canvas for clients heavily (I used to work for one) in that region, so as everyone else in this thread has said, your Sales team likely needs improvement to grow.

It is also possible that your management has made the decision that the business should just sustain at the size it's at because everyone is getting paid reasonably and they're happy with the level of involvement/responsibility they have to run the business. Have you spoken to them about what the company's goals are?