I was in the same situation, you won't get the receipt number if you call up TCS as you the beneficiary. So other ways to get your receipt number is
1. Try speak to employer and ask him to provide you the reference number tell him that you need it for your reference.
2. If not ask your attorney, most of the time they are very loyal to employers.
3. If non of the above is working out, walking into your closest immgiration office provide them all your details and if you lucky they might let you know
(This advice was give to me by an immigration lawyer not sure it will work as I didn't try this option.)
Good Luck.