State Bank Of India [SBI] — Unwanted Madate fail charges

Currently i do have one ongoing Loan with bajaj finserv ltd. associated ecs with SBI bank. Sometimes i forgot to fund my account with cash for ecs but not neededly. More than Rs.1300 they charged me that mandate fail charges But i mostly deposit money on that same date in which that ecs wont bounce, but even though they had charged saying that money was not on that day. but now they had charged me quoting dated 22/10/2020. in which no ecs will fall on that date and my mandate fail date will be only with 2nd of every month. unwantedly they charged me for last month (october) in which my ecs passed successfully.
if you refund my money it would be greatful

kindly check and do the needfull