Ecs Mandate dishonoured inspite of required balance existing

Respected lawyers kindly help me out.i had taken a four wheeler loan in one renowned finance company and the mandate date is 3rd of every month and the amount is 7100.This month on second i had only 1569 and by 11:50 am i had transferred 7000 to my account through imps and it was immediately credited to my account.on third my salary was also credited.The amount of 7400 dint go through ecs and on fourth i recieved a message from the finance company that my mandate had been dishonoured.i checked with my bank they said everything was ok on that day and there was no hold on my account.when i enquired the finance company they say once after they recieve the reason from the clearing house they can tell anything but now the amount that i need to pay stands at 7677.kindly tell me as to what i should do.Thanks in advance