HDFC Bank — fastag

About 3 weeks back (on 1st of Jan 2020) HDFC manually debited INR 335 from my Fastag account with no clarity on why this was deducted. I emailed them multiple times - there was no response to the emails, called 3 times (I was told that the system is down every single time) and contacted on Twitter (first time they asked me to email and call, there was no response for subsequent messages). Now they have manually deducted another INR 200. Though the amount is not big, their utter disregard and indifference towards the customers are alarming.