Problem for ECS activation

I opted ECS for my car loan. Car loan is with State bank of India, Chinchwad and ECS from Ing vysya bank. After completion of  loan processing , i collected ECS form from SBI on 30th June 2012. As EMI amount on documents was mentioned as 11500, i submitted form in ING with same detail and one copy to SBI.

Due to some technical problem, ECS debit was not activated in SBI  and i had to pay by net banking.
In October I went to SBI branch and asked for status of ECS activation. They told that it will be activated next month and asked me  to again pay by cheque or online. They verified my account and told me that EMI is 11501. And you paid Rs. 11500/- last three months so this time pay 11504.
I paid Rs. 11504/- by net banking again.
In November also ECS was not activated so again i paid by net-banking.
 In December, SBI informed that ECS is activated when i went to branch and this month it will be executed. On 12th December, ECS was executed when I logged into to SBI CAR loan account online but my ING account was not debited. There was ECS returned details in SBI account online dated 15th Dec. (return code = 5)  I got sms from SBI that ECS returned due to insufficient funds. There was enough balance in my account. I went to branch for confirmation and they informed that there may be some technical issue as they were also not sure. They asked me to wait till 20th Dec. I again paid using net-banking on 21st Dec.

In January, ECS was again executed but got reversed on 15th. I paid amount again. As ECS was not executed second time, i started thinking what may be the issue. I searched online the meaning of return code 5 and found the meaning as exceeds arrangements.

 I was doubtful that amount difference (ECS form with 11500 and actual ECS of 11501) may be the issue. So i went to ING branch at FC road. They confirmed that actual ECS amount should not greater than the details provided while activating ECS. They provided me one form for amount correction. I submitted the form to ING. ECS correction charges (around RS. 50) got deducted from my ING account.
On 12th February, my ING account is debitted with Rs. 11501. I was very much relieved when i got the message. This was first time i opted for ECS so i was very much new to all these things. (ECS may not get executed if actual ECS amount is more). I was only aware that if there is insufficient balance in account, ECS  is not getting executed and some fine is charged for ECS failure. In my case there was no Fine as i had enough balance in my account. So I was very confused why it is not getting executed.
I am sharing this because it may be helpful to someone.