EFT\ACH cancellation

We are implementing EFT/ACH payment via financial gateway and wanted to understand the return/cancellation of the EFT.  How does Peoplesoft handles cancellation  of electronic payment which have already been sent to the bank (are cancellation of EFT included in the electronic payment file?).  We have 5 day waiting/hold time at the  bank before the actual money is credited to the supplier account.   Also what process/files are returned for ACH/EFT return status.   

Any insight will be helpful.

thanks