Hello, I recently used a website online to complete an assignment for my university, they contacted me on whatsapp, they sent me the assignment and i submitted it, they asked for a screenshot of the work submitted, and even though it sounded strange I sent it, after I made the payment they texted me saying I had to pay 999$ (refounable), for the release of the copyrights.

I told them i didn't have that kind of money and complained about the fact they didn't say anything before, they told me I could pay half now and half later so I paid the half since they were threatening to contact my school, after a few days they texted me for the other half otherwise there would have been a fine and I would have had to pay more.

So I paid the other half but late so they asked me to pay more or they would contact my school, they have the screenshot I sent and others data about me like my passport number which I didn't share, now i sent a bank transfer, in the meantime I got my exam back and I failed so

I asked for a refund they asked a screenshot and I sent it, now they told me once my payment of 300 arrives, it takes a few days since it's international, they will refund me, they also asked me to send my IBAN, but I didn't yet since they told me I have to wait anyways.

I'm really scared they will contact my school, I know it was very stupid of me the whole thing but I don't know what to do, they have the name of my school, what should I do? I'm desperate, I can still take back the 300, but the other money is gone?, I'm really scared and I can't risk being expelled please help me