Hi dianellaphysioth,
Thank you for reaching out to us.
Duplicate transactions can be caused by a number of things, its hard to pin point exactly what is going on without a visual though.
You are definitely able to go through your reports to see if there are duplicates present to then delete them directly from the reports themselves.
You are also able to exclude certain transactions that you believe are duplicates directly from the bank feed so that you stop them from coming in completely.
There is also a scenario where you might be manually creating a Receive Payment transaction to then match to an open invoice, whilst also adding the same transaction via the bank feed causing the duplication (this is a common one I find).
I hope this gives you some more insight on how these duplicates might be coming up.
Kristian.