Hi, Can I claim the refund for incorrectly deducted CPP amount from my salary. Form: T4 at box 16 in mentioned as $ 2000 and in IT Return at Line 448 mentioned as $100.

Basically I am on "work permit visa" in Canada and I am paying the retirement benefit back in my home country India and as per the Indian & Canadian Govt agreement CPP should not be deducted from my Salary in Canada, but it got deducted by my payroll team by mistake and mentioned to claim that back during return filing here in Canada. I have mentioned the incorrect amount at Line 448 in the return and got the assessment done by the CRA. 
Now I notice that I have not fully claimed the refund of CPP amount at Line 448 in the return.
Please advise can I submit T1 Adjustment Request for this issue. Thank you.

Seniors and students

Only enter Box D and Box G from the Releve 6 slip. The amount for benefits received will transfer from the T4E.