Hi
I fully understand that it is unethical on Bajaj Finance to recover installments before first disbursement.
The best option would be for you to meet the officials of Bajaj Finance in Person and resolve the issue(normally bajaj finance resolves such issues very fast to my knowledge).
However please also be informed that Bajaj FInance never has the habit of refunding the money collected as EMI.
At the most they do is reduce some notional amount of Rs3000 or so depending on the EMI Amount.
In some cases, they also reduce their processing fees to some extent.
So you should negotiate with branch officials of Bajaj Finance (ignore the sales guy) for
a) interest for advance EMI or
b) Reduction in processing fee or
c) Compensation
which ever is higher.
Please do not stop your ECS due on 2nd june as then Bajaj finance will then resort to unnecessary blame game and this will affect your CIBIL Rating.
Hope this helps.