Goibibo.com — Charged more money than was reflecting on the site while payment

Website:

www.goibibo.com/

Goibibo has a system of Gocash, in which you can pay certain amount by Gocash and the rest by cash. While making the payment of a ticket worth rupees 7300, till the payment gateway it was showing that 6000 something rupees would be deducted, till the time I filled my debit card details and clicked the pay option. But they end they end up charging the complete amount of the ticket of rs 7315. you can;t be saying that you are charging this amount and then charge some other amount.