The income I entered as foreign income while filing my taxes, registered as Canadian income on the actual return. How can I fix this?

I only lived in Canada for 21 days in the calendar year of 2017, before moving back home to Europe after one and a half year in Canada on IEC visas. It does not make sense to me that my income after moving back to my home country should have any influence on the Canadian taxes whatsoever, but either way I at least want it to be entered correctly in the return.

I would love to get some help with my specific case, but living in Europe with a European phone number means that calling your help desk would cost me a fortune.