On the Tournaments --> Tournaments tab, click the Amount Won column - that will sort the report by Amount Won. You should see your "big win" at the very top. Note the Tourney #. With Auto Import stopped, then click Tournaments --> Enter Holdem Results. Locate that tournament by Tourney # (again you can click that column to sort by it). Click on that tournament, and in the Results tab below click on yourself and edit the Amount Won on the right and click Save. That will update your information.
If you have the original hand histories that imported improperly, please also send them to us via the
support system so that we can investigate what caused the error and get it resolved permanently.