Retrive Money

For taking legal action you need evidence. Oral agreement is valid but if another party denies that agreement then ypu need written evidence to prove. If you have transfered through bank then show the bank entry as evidence. Any kind of evidence is okay which proves that the transaction between you both took place.

Send him a legal notice and if he does not respond file a suit for recovery. But this will be helpful only if ypu have written evidence of him taking money from you.