ICICI Bank — Wrong over limit charges

Credit card bill generated on - 18 July 2021
Card No: [protected]
Sequence of events:
I was trying to make online payment around a moth back using my icici credit card, suddenly I started receiving multiple messages regarding same transaction and also Icici representative started calling me multiple time in night around 10.30 pm, he told me that it could be a suspected fraud. So in panicked situation I reduced my credit card limit to 2000 to limit losses. And after that I blocked my card.
Since the card was blocked I was not able to see it in internet banking app anymore
Then yesterday I received statement with Rs 500 overlimit fees
As per my understanding, setting up custom limit from my end is for my way to limit expenses. I am still not exceeding bank's credit limit, so why overlimit fees was charged.
Tried calling customer care but they did not help, also they refused to take my complaint against this policy