Undo Last Bank Statement Import

Undo Last Bank Statement Import

I have import my bank statement but have the description and payee mapped incorrectly. Now I have done about 2mth worth of invoice and was about to my expenses such as citylink and personal spend such as transfer to holiday account and now none of the rules that were setup work.. I dont know what will happen if I undo the last import .. or if there is any other way to fix the issues because the vital bit of info such as "citylink" or "holiday" cannot be add as it cannot be see by any of the feed ..please help