You can claim a refund for up two years from the date of contribution.
To claim a refund, prepare:
An explanation letter, containing details of the mistake (example: incorrectly claimed travel allowance)
Copy of IC
Copy of the Form A (with the incorrect contribution) or your company's EPF monthly statement (from the month the incorrect contribution was made).
Log in to i-Akaun (if you don't have an i-Akaun see here).
Fill out Form A stating the month for which you want to make to the adjustment payment.