None

When I requested a salary increase, I was brushed off with the explanation that they would schedule a more tightly packed workload for me, so my performance bonus—and therefore my pay—would be higher.

The salary adjustment is made in the form of a performance bonus: you receive it if you meet the work requirements, and it is deducted if you do not. It is variable.

It is not part of the base salary. In other words, there is still no salary increase; you simply do more work to receive more bonuses.