Releiving Letter & Recovery Amount not provided by employer

Dear Sir, I was working at India Infoline Ltd as a Branch Manager, it's basic nature of business is GOLD LOAN, where two Custodians being responsible for Gold Valuation and Cash Verification & I was 1st Custodian of it. the Branch timing was 9.30 am to 6.00 pm as on 09.07.2015, evening appx 5.30 PM a customer Named Kalyan Soni has come to release their Gold of Rs. 23 00 000 where the total outstanding of his Gold was above 29 00 000, in 14 loan accounts. He transfered Rs 10 00 000/- by RTGS and Rs. 13 00 000/- he carried by cash. My cash staff chacked all the cash, and I updated RTGS amount by mailing to concern department. Customer was started shouting to release Gold early, finally he made us frustrated to let him go early, we kept the Gold packets of approx 500000/- and Hand overed the Gold to him. but we didn't calculated the transaction of received amount & Released Loan Value. After going we started the calculation peacefully, then we found that Release Gold Loan value was rs. 23 48 890/- while we were received only 23 00 000/-. I started calling to customer but he was started refusing to meet me for balance payment by making me fool with different ideas., as per co. circular it was my responsibility to immediately inform to seniors on mail, but we did the mistake, we didn't informed and closed the branch with Shortage cash. we tried to recover the amount for 3 days and 4th day was Sunday. As on Monday 13.07.2015 auditor came to Branch and Found the shortage at the Branch and reported the same. Area Manager emailed to recover the amount immediately or FIR against Custodians. I visited to customer address with co's Recovery officer but customer was not at home. and wasn't picking my calls also. to prevent me & my joint custodian I arranged the cash from my Relative and recovered same day, but area manager mailed for Open Inventory Audit by saying all the staff need to terminate. after some days I received show cause notice from co. by asking WHY WE DIDN'T INFORMED SENIORS FOR 4 DAYS. as discussed with my manager I replied to co. on email by apologising for my mistake and assured not to repeat any mistake as there was no mistake for last 4 years of service. But than to co. Terminated me on the ground of Non reply of Show Cause Notice & not released the Experience Letter to me. but not terminated to another custodian and taken Resign. Now I communicating with the customer for the amount which I have submitted to co. as recovery but he is not willing to pay and saying that if co. will ask me to pay than I will think. now you are not the co. staff. co. staff & managers also not supporting me. Please tell me is this the co. responsibility to recover my Cash from customer because they have terminated me & not provided receiving Letter also. am I legally authorised to FIR against Customer personally or co. for the same. or my amount will be lost.