中加免稅協議 international tax center 詢問是否移民申請是否屬歧視

各位好，又是報稅季節。我是在加的國際留學生，根據中加免稅協議 artical 19 china/Canada tax convention. 國際留學生收入是不收稅的。依該條款，我詢問international tax center, 被告知他們內部有一個規定（internal instructions）： 如果我遞交了移民申請，這個條款就不適用。我認為這是一個歧視性的內部政策；
我把artical 19的原文附上。大家給點建議，1）看看他們的internal instructions 是不是歧視性政策和違反同時也藐視中國和加拿大的國際協定。2）我是否有權利據決告知他們我是否遞交了移民申請.

Article l9
Students

Payments which a student, apprentice or business trainee who is, or was immediately before visiting a Contracting State, a resident of the other Contracting State and who is present in the first-mentioned Contracting State solely for the purpose of his education or training receives for the purpose of his maintenance, education or training shall not be taxed in that Contracting State.