Cosmo Infotex — data entry

I have taken work from home through this company and submitted the work in 5 days with an agreement to receive 20, 000 as salary. After the work is completed they are asking for refundable processing charges. Please let me know whether the company if genuine or fake. The person who called me is sindhu. They also gave me a approval letter in pdf format stating that my work is approved and i am selected for 12 months project as i have 93.3% accuracy in my work
Same cosmo infotex company, asking for (3581 /rupees) refundable processing charges after the work got completed.
And i had paid amount till now salary was not credited they are also not lifting the call
What i have to do now friends any suggestions from you