Dude first of all understand the nature of business, things here not work as you want, you want proof of his previous work but why would he provide proof and reveal name of the company to a random guy like you, if you really want proof of his previous work then you should provide him proof of your previous work at first step then ask from him as well

To be honest by seeing your comments i can clealy say that either you dont have any knowlege of such work or you are out of your mind

You think and behave like as these work are as easy as withdrawling money and receipt from ATM

Why dont you do proper research before commenting on such silly way and disturving every single member of the forum