National Highways Authority Of India [NHAI] — deduction of amount from fast tag

I had travelled through nelamangala tollgate through nh47 - bangalore - to tumkur on 12.08.2018. There is a queue in fasttag, hence i went through manual lane and gave rs 70/- for up and doen journey. The counter man gives refund of 20 /- and gives one way journey fare ticket, where as in notice two fare is 35/-. After pass on the toll my fast tag account also got debited for 20/-. Kindly reverse the amount.

Dear customer, your etc account no. 20580337, vehicle no. Majaxxmrkajl45013 has been debited rs 20.00 on[protected]:59:47 for toll charges at kulumapalya toll plaza plaza on[protected]:39:32. Available balance is rs 684.92.

The message also attached here with for your reference.