HDFC Bank — Legal complaint for card charges

Dear Team
My name is Bhanwal lal kumawat and i am a advocate and i am having a credit ending with 1927 .
In last month due to certain medical emergencies i paid card amount slightly late and well communicated same with your executive he said that no amount will be charge will be levied .
I paid most of amount .
Then suddenly now with out any prior information or call you guys had levied a charge of Inr 6618 on my card on 21/01/2022.This is equal to household expanses of a person .

How you guys can do this without my prior intimation .
This is unethical and i will do whatever need to do .
Please refund charges else i will sue you guys in banking ombudsmned and consumer court

Revert on mail only.
Regards
Bhanwar lal kumawat
Card: 4577***1927