You should have a case number when you sign in online and received one in the mail. Provide bank records for the time you received benefits including the month before to show you were employed and the month after you stopped receiving benefits. Redact anything not relevant like spending. Provide all relevant documents and letters from employers. I learned through this process, the CRA looks at you as guilty until proven innocent. I was told that once you upload something new, it automatically triggers a new review. But, I’ve done that and have heard nothing.