How do i claim foreign tax credit, which i paid social security and medicare taxes to US?

I works in a US company from home in Canada. The company has Canadian payroll. They issue both W2 and T4. My income for the days i worked in Canada is considered as Canadian income. However the payroll deducted the social security tax and medicare tax for the whole year, I guess they consider me as a US employee.

I only worked in US for several days last year and had small amount US income, which is much less than what i  paid for society tax and medicare tax. TurboTax puts my Foreign Tax Credits to Carry-Forwards to Future Years incorrectly. How can i claim it back?