Kia India - Excess amount paid not yet refunded

I have purchased a New Kia Sonet from Shreenath Kia Motors Pvt. Ltd and made the booking on **th Feb **** by paying Rs. ***** from my credit card.
The payment got debited from my card and after few days I got confirmation from Kia also that the amount is credited to their central office account and you can pay the balance amount at the time of delivery.
But few days later they informed me that they are unable to trace the amount and you can pay full amount and once the issue will be resolved we will reverse the booking amount to you.
I paid the full amount at the time of delivery on **th March **** and till now I am following up with them for reversal of excess amount and not getting any proper response from them.