Kotak Bank Credit Card - Payment deduction after paid bill

I use the Kotak bank credit card. I paid my bill * July **** on the payment date in the morning. But Kotak bank application failed to recognise customer bill paid or not resultant they charged me *** Rs fees and GST amount ***.** in the afternoon. This is happening with me the third time. When I talk to them then they give me an illogical statement. They say due to failure auto-debit service they charge me. They suggested I paid a bill before * days of payment date. Why I pay the bill before the payment date. I have concerned about it. When the system develops then everything should be checked because of customer use in any way. They never check customer transaction in auto debit service. If the customer has paid the bill then why auto-debit service cron job did not check customer paid bills. The first time they reversed only *** INR fees, not GST. The second time they reversed the total amount. But the third time they are refusing me to reverse amount. While every time I have told them that it is your system's fault. Your system does not check customer transaction while deducting payment. but they don't want to hear this.