Absolutely right...you should monitor your limit....but what is your limit was deliberatley being kept too low for your business cash flow patterns.
As businesses grow so does their need for working capital finance typically financed using overdrafts. The prudent banker knows this and ensures the right level of overdraft finance is in place.
I'm writing of a practice where the banker knowingly kept the limit artificially lower than it should have been and then managed the performance of the account by using shadow permissions...The specific objective this was to increase the level of fees and interest earned. This was widespread practice.