ICICI Bank — Frequent ECS charges deducted from Account

Through out the year FY 22-23, Total 11times ICICI BANK deducted ECS Charge of 590 rupees. When I reach out to Customer care, I got to know this amount got deducted, as my account didn't have sufficient balance (not minimum balance) to send money to one of my mutual fund biller. I have few questions
1. Can bank charge any amount of money, as they wish for ECS? Is there any RBI rule for this
2. How can I get refund of my ECS deduction?

Cc: Dropping an email is the easiest way to divert this complaint out of the forum. I want my answer here