Road Tax leaving Delhi airport for Gurgaon

I arrived in India for the first time, early this morning.
I was told at the Delhi police Prepaid taxi desk that the road tax for going to Gurgaon was 42 Rupees.
The driver of the cab told me that it was 100 rupees.
I told him that the police told me 42, and that was all I was going to pay.
Was the trying to pull a fast one on me?

here is the link: http://dgexpressway.com/tollrates.htm
toll should be 21 rs & they are entitled to charge you return toll. best option is to tell the driver that you will pay toll on your own at the gate, so you know exactly how much to pay as per the printed receipt.

Thanks for taking the time to reply to me.
It's my first time here, so I was just unsure.

when you are going to Gurgaon you need to pay Rs. 21 for each entry as toll tax and Rs. 45 as MCD tax (which drivers normally dont pay)!!