(1) Regulations shall provide for the return, subject to any conditions, restrictions and deductions specified in the regulations, of so much of any employment contribution paid by an employed contributor or voluntary contribution payable under section 22 by a voluntary contributor whose entry into insurance occurred -
(a) after he had attained the age of 60 years,
(b) after he had attained the age of 58 years in the case of a person who attained the age of 57 years on or after the 1st day of July, 1974,
(c) after he had attained the age of 57 years in the case of a person who attained the age of 56 years on or after the 1st day of April, 1975, or
(d) after he had attained the age of 56 years in the case of a person who attained the age of 55 years on or after the 1st day of October, 1977,
as is determined in accordance with the regulations to have been paid in respect of old age (contributory) pension.
(a) In the case of a person who attained the age of 56 years on or after t