I don't think that's a subcharge though, that's a penalization if anything and I have a feeling it's probably illegal, at least would be where I come from. I don't think I'd ever work for a company that would penalize their workers by charging them fees. I'd quit that job fast.
Seriously it is the same thing that I was going to do if I were to find myself in such a situation whereby my boss will decide to be penalising me for things that shouldn't have to affect my salary. I will still put in a lot of work to make sure that I get paid, only for me to end up being penalized for unnecessary excuses.