Personal — Excess Toll charged even after using fastag on round trip

Respect sir
I was travelling from New Delhi to Rajasthan On Sunday while crossing Manesar toll I paid using fastag and Rs. 70 was charged. I made the round trip back to New Delhi within 24 hours and paid again using fastag and again I was charged rs 70.
This is a fraud that has been done by the NHAI toll official at the Manesar toll. acc. To the govt rules while using fastag for roundtrip the balance amount is charged i.e. I was supposed to br charged around rs. 100 but instead I was charged with rs 140.