UBER - Too much Toll Tax Charged

I booked a cap on *th Nov from Vasundhara, Ghaziabad to Shahdara, Delhi. Initial amount shown to me was Rs. *** (this was including Rs.*** toll tax) but i end up paying Rs. ***.**. Actual toll tax for this trip should be only Rs. *** as shown earlier. But later driver (chetan) did something and final bill was generated with Rs. *** as toll tax. When i refused to pay extra toll tax amount, he said your money will be refunded by company.