CPP and OAS are subject to Part XIII tax. Part XIII tax is not refundable, unless you are Electing under Section 216 (rental income or timber royalties), or Electing under section 217 (certain Canadian pension income).

Tried under 217, filled our schedule A and B but no refund.

Another question...
I recently paid Turbo Tax online $268 ($120x 2) cdn do our non resident 2023 tax filing. I have yet to find out if this can be done (as it's not a "simple return". Should I contact a Turbo Tax filer to do this or will I be told they don't do non resident taxes? Our global income is canada only.

If you're using Full Service, you can contact a Full Service agent by clicking on “Documents” on the top left of the page, then “I have questions or need help with docs”. They should be able to answer your questions.