Videocon Industries — videocon d2h wrongly balance debited from account

Hello,
I have complained to the d2h customer care about my set-top box not performing properly, the next day their engineer visited my place any asked me to change my set-top box as it has some faults in that, he did replaced the box and changed me with rs - 450/- which i paid him in cash.
On the same day i got message displaying "insufficient balance" on my tv screen.
I do call the d2h customer care and i have been told that the charges are debited because i have replaced my set-top box, but their engineer who visited my place had already taken the amount of rs - 450/- from me. The customer care people registered my complain and i was said that the amount will be credited to my account within 24 hours. I have already registered 3 complaints and yet my problem is not solved.
My customer id is 5729367