Tamil Nadu State Transport Corporation [TNSTC] — balance amount not return

Address:

No 10 3rd street, kannappaswamy kovil nagar, kavangarai, Puzhal, Chennai - 66, 600066

I was travel poonamallee to kanchipuram - 3/8/19 (2.40 pm) in the bus 76 dex. I gave $ 500 for the ticket to kanchipuram. The ticket amount was $50, balance amount collect later said by conductor and written it in the back side of the ticket. I get down in the kanchipuram bus depot (Olimugamathupettai). The conductor did not gave the balance amount and i also forgot that.
Enquiry about the balance amount :
— *4/8/19 poonamallee bus terminus, time keeper at 5.15pm
*4/8/19 kanchipuram old bus terminus, computer section at 7.20 pm,
*4/8/19 orrikai ii depot, computer section at 8.45 pm.
They all said that bus ticket not comes under our control. They diverted to gm office
On 8/8/19 i sent the register letter to gm office. (Kanchipuram ponnerikarai) there is no response and reply about that.
I attached photo copy of the ticket. Please consider my request and take step as soon as possible to get my balance amount $450.
I waiting for your reply sir, i hope take action quickly about this matter.