Temporary pay cuts for performance management

I work for a transcription company that pays by production and conducts monthly to quarterly audits of my work. Additionally, if a transcriptionist can't make out a word or find a term, she can leave a blank and send it to the QA team to see if they can fill in the blank. From the company's perspective, this results in paying 2 people to do 1 report.

Recently, in an effort to reduce the amount of work going to the QA team, my company implemented a new policy in which we can decide whether to send reports with blanks to the QA team, or straight to the client. We have a 5% allowance for work sent to QA; if we send over 5% of our work to the QA team, they will change our pay rate, dropping if by 3 cents per line of transcription. This, in effect, will result in a 50% cut in pay for all that work that went to QA.

I didn't pass my most recent quality audit, and now all of my work has to be reviewed by the QA team instead of just a sampling. Since ALL of my work will now be going to the QA team, I am receiving a 50% pay cut for ALL my work, minus the 5% allowance. This will undoubtedly put me under minimum wage.

Once I pass my next audit, my pay will be restored to the normal rate. However, they said my next audit may be next week - they aren't sure when they will get to it.

Interestingly, that 3 cents per line that they are cutting my salary by is exactly how much the QA Team is paid to review my report. So basically, they are taking the QA Team's salary out of my pocket.

Is this legal? Is it ethical? Is it reportable to anyone, or do we just have to take it? I don't know how they can expect anyone to live on a 50% pay cut.

Any info you can provide would be helpful.

Thank you.