i ahve an instance of harassment unduly by a financial institution.i want myself clarified first for the cloud of doubts prevailing in my mind about the legal position:-

the case is as follows.
it is a hirepurchase agreement for car.at the time of execution the institution got the ECS mandate from me.subsequently due to the slowdown in my industry and the natural calamities the business could not flourish as has been estimated and the remittance to my a/c for the bills due to em happen to come irregularly disabling me carrying out the earlier commitments.result the ECS mandate could not be made use of by the financial institution.there were instasnces of cheeque(ECS) returns.but every returned instrument (instruction of ECS unpaid)has been mad good subsequently by demand drafts under proper receipts by the collection agent of the institituition.In the meantime the institution nhas used the cheques given for security to collect the instalment which cheque also got bounced but subsequently mede good by demand draft.The institituition got a lawer notice served on me for which i replied that the amount due for the returned chque has been paid under proper receipt.now thwere are 3 EMI s due for the a/c out which one is for the current month and the rest yet to fall due.At this juncture the institution got the audocity to file a criminal complaint against me for the retruned cheque , though the it has realised the amount due for the said returned cheque.how is it justifiable.what is the remedy open to me.Is the institute entititled under the process of law to file a criminal case though it has realised the money due for it ,just under the technicality of the law in the name and under section 138..can anybody suggest me the correct course of action and the remedies open to me.