12. A person, except a person who, between 1 July 1965 and 30 June 1973, became a pensioner or became entitled to a deferred annuity under the Teachers Pension Plan or the Civil Service Superannuation Plan, must, to become eligible for benefits under this plan, redeem the years or parts of a year of past service in an employment with a body contemplated in the Government and Public Employees Retirement Plan or with a body which, in the opinion of the Commission, would have been contemplated therein had it not ceased to exist. Any pension credit that may have been granted under section 86, 100 or 104 of the Act respecting the Government and Public Employees Retirement Plan (chapter R-10) is cancelled and the service that entitled the person to the pension credit is deemed to be credited to him under this division.
In no case, however, may a person redeem the years or parts of a year in respect of a pension, a deferred annuity or a paid-up annuity, within the meaning of section 76 of the Act respecting the Government and Public Employees Retirement Plan, is payable under a pension plan. The same applies to the years and parts of a year in respect of which a pension credit is payable under section 101 of the Act respecting the Government and Public Employees Retirement Plan.