On your October 17, 2019 pay, there was a deduction for union dues arrears. This should have been the final deduction for union dues arrears due to the pay equity decision.
Unfortunately, Canada Post made an error in the calculation. They did not deduct union dues on the retroactive rest period allowance payment (RPA).
How Much Will I Pay?
The amount of this deduction will vary depending on your Schedule “A” hours and how much you paid in union dues in each year covered by the retroactive payment