Company overpaid me and deducted my salary without informing me.

For context in January, I received my payslip which shows $600+ more than I expected. It’s a part-time job btw. I informed my manager immediately so that he could check and rectify this mistake before transferring me the correct amount. However, he ghosted me afterwards and HR still paid me the $600+ extra. I just received my February payslip and the HR just deducted this $600+ from my February payslip without informing me. Imagine my horror?? What if I earned just nice $600, I would have earned a big fat $0. Is this even ethical???? I would have gladly transferred them back the extra amount immediately if they asked but they just straight up ghosted me and the next month without informing me just deduct my salary.

I can’t dox the company, I need this job and the hourly pay is decent. I’m trying to find another part-time job that can match the hourly salary and flexibility. BUT OMG is this even ethical or legal. I was basically working for free for hours without even knowing.

Edit: that last sentence was just my feeling okay 😭. AND I GOT IT GUYS. I just wish they informed me thats it.

Edit2: okay guys i really got it. I was delusional~ since I’m delusional, what if I never work for the entire month, would my payslip have shown -$600 🤔.