Hi there

Sorry hear that,but as above this is scam which has happen to several people like in US,Canada or in UK,few moths back this happen to my good friend when they ask her for remote control over her PC.At the end I've been able to recover at least most important things for her

Not sure how bad is it yours,but yuo can try download Live CD distro(Knoppix) with this you should be able to recover most of the things or if yours PC is locked or yours account is locked then I would try NTPassword,I've used this and its best and its free 

Link on this SW is here

http://pogostick.net/~pnh/ntpasswd/

But if you will do that,I would download too,Combofix and few other Antimalware plugins SW like is AdwCleaner link is here http://www.bleepingcomputer.com/download/adwcleaner/ and good old Malwarebytes Anti Malware 

If they deleted any files,you should be still able to recover them via free Recuva,i've used this too with good success

Hope this helps there

Thanks,Jura