33. A beneficiary who receives a pension in an amount that is less than the pension he would receive but for the application of section 32 is entitled to the refund of that part of his contributions which corresponds to the ratio by which the pension credits exceed the amount of the pension granted to him.
The pension credits reduced or cancelled by reason of the withdrawal of contributions shall be, first, those granted during the most recent year of service and, then, those granted during each year preceding it.