I took an academic thesis writing services, now that the thesis is submitted they contacted me 2 days ago stating that the expert writers have left the company and they are threatening the students to give their name to the university.

They also mentioned that don't worry our legal team is in place you will have to prepare a NDA document and Copy right certificate which will cost you 1699 pounds and everything will be sorted. They pushed me too much stating that your career is at risk, if you don't pay then you would have to pay a greater fine by department of education .
So somehow I convinced them to for 800 pounds (very stupid of me). Later when I constantly asked for he documents they said that the team has left for the day they will be in touch with you from Monday. Today morning i get an message that the lawyer is asking for 2000pounds to sign the NDA and the copyright certificate otherwise the documents will be baseless. They also told me this money will go for removing my data from all the portals and their database.
I asked them to email me everything that they are saying so that I have the proof but they denied stating the gravity of this situation is very sensitive. they aren't even letting me speak with the CEO/ head of the management of the company as i would need a prior appointment since they are very busy.
Now they have given me 2 hours to send them 2000 pounds. Need legal advice and help.