National Highways Authority Of India [NHAI] — I am complaining about excess toll deduction for my Maruti Suzuki CIAZ ZXI car

Sir,
I am using my Maruti Suzuki Ciaz ZXi model car with registration TN69BA3931 since its purchase in January 2017. After implementation of Fastag by Government of India, I have purchased Fastag from SBI and is regularly using the same.. There was no complaint of excess deduction till March 2020 i.e.declaration of lock down due to COVID 19.. Due to travel restrictions, I have not travelled till Oct 2020. On 16.10.2020 i travelled to Madurai and initially normal fare was only deducted in Pudur pandiyapuram and Elliarpathy toll gates. After a period of one week additional toll deductions @ Rs.335/- i.e. toll of Multiaxle vehicle was deducted. for forward and return journeys. I didnot understand the reason for excess deduction and hoped that due to error, excess deduction has taken place and the same will be reverted in short time. I didnot make any complaint of excess deduction. However, to my surprise every time excess fare was deducted after few days of my journey.
To sort out the problem, i once stopped at Pudurpandiyapuram and Elliyarpathy toll gates and discussed with the stafff and mangers. But they have replied that problem is not with them and they are not responsible for the excess toll deduction. After my complaint to SBI Fastag through helpline, i have received Rs 1005/- as refund. However, further an amount of Rs 2680/- is due to be refunded.
I am enclosing herewith a copy of RC Book, Vehicle image, Print out of toll transactions from 01.04.2020 to 15.03.2021 and summary of excess deduction done at toll gates for your perusal.
I am a central Government Officer working with Department of Atomic Energy knowing the govt. initiatives. If this type of excess toll deduction is taking place repeatedly and cannot be set right looks illogical. Hence i request you to arrange for refund of excess deduction as per my claim and prevent recurring of this in future.
Yours sincerely,
R.Gurumohan..